
WOOD 



PATTERN-MAKING 



puKriELp 







Book 



Goipght]^"_ 



COPYRIGHT DEPOSIT. 







•■Si 

o 



Wood Pattern -Making 

The Fundamental Principles and Elementary 

Practice of the Art. To which is 

added an appendix on the Care 

and Use of Woodworking, 

(Bench) Tools. 



BY 

Horace Traiton Purfiki^d 

Instructor in Woodwork and Pattern Making, in the 

Department of Engineering 

OF THK 

University of Michigan 



PUBIvISHED BY THE AUTHOR 

1906 

THE SCHARF TAG, LABEL & BOX CO. 
YPSILANTI, MICH. 



■^0 



-p, 



n 



LIBRARY ntCGNGRESS 
Two Conies Received 

MAY 5 !906 

^ CoDyrifiiii Entry 
CLAS-v OC '«o. 

COP^r B, 



COPYRIGHT, 1906, BY 
HORACE TRAITON PURFIELD 



(q-'\(o1^0 



PREFACE 

An experience of seventeen years in teaching pat- 
tern-making and kindered subjects has made me feel 
the great need of such a work as this which I now offer 
as a text -book for students in technical and manual 
training schools, and universities. A number of 
excellent books on the subject have been published, to 
be sure, but most of them assume on their reader's part 
previous acquaintance with the fundamental ideas of 
pattern -making; such as do treat at all of the elementary 
part of the subject, happen to be works of an exhaustive 
character, which are consequently too expensive for use 
as text -books. The present work, therefore, will, it is 
hoped, find a field of usefulness for itself. 

It is of course to be recognized that as pattern -mak- 
ing is an art, it cannot be learned simply by reading any 
book on the subject; but only by practice. Still a text- 
book may afford valuable assistance even to the artisan. 
This work, however, has a further and more important 
purpose, — that of imparting to the engineer or the drafts- 
man the fundamental principles of pattern -making. For 
only as he is In possession of these can he make designs 
for patterns in accordance with which shop work can be 
performed in the most efl&cient and most economical 
manner. The reader should also understand that this 
work, being designed only as an elementary treatise, in 
no way exhausts the subject. It is claimed however, 
that the examples of pattern -making submitted indicate, 
on the whole, the best methods of construction and those 
most easily understood by the student. 



VI PREFACE 

In preparing the body of this work, I have received 

many valuable suggestions which have been incorporated 

herewith, and which will have contributed to any success 

the book may attain. The works of many previous 

writers on the subject have been consulted also; for 

specific ideas derived from them credit should be given 

to Joshua Rose, M. E., J. McKim Chase, and P. S. 

Dingey. In preparing the appendix considerable help 

was afforded me by the little book of W. F. M. Goss, 

on "Bench Work in Wood." With these few words of 

introduction, I leave the book to its readers with the 

hope that it will assist them to master the important 

subject of which it treats. 

H. T. P. 



CONTENTS 



CHAP. 










PAGE 




Preface 


V 




List of Ili^ustrations 








VIII 


I. 


INTRPPUCTION 








1 


n. 


Molding .... 








6. 


III. 


Generai, Principi.es 








12: 


IV. 


Materials 








20 


V. 


Fillets .... 








30 


xVI. 


Cores . . ... 


i . • • 






37 


xVII. 


Moldkr's Joints or Partings 






46 


VIII. 


CpNSTRUCTIONAL JOINTS . 






55 


IX. 


Special Types of Patterns . . . 






66 


X. 


Plate Work and Irregular Parting 






. 83 


XI. 


Pulley Patterns .... 






93 


XII. 


Patterns for Cast Gears 






108 


>^III. 


PiPE^ Fittings, . 






126 


XIV. 


Miscellane;ous . , . 






132 




Stove Pattern-Making 


, , 






145 



APPENDIX 

Reading Mechanical (Working) Drawings . . . 154 

Lumber 161 

Pattern Turning 199 

^LANES and Plane-Like Tools 188 

Cutting Wedges . . , 195 

Boring Tools 181 

Saws . . . . Ill 

Index .212 



UST OF IIvLUSTRATlONS 



FULL 

* 'Oliver" Combination Lathe 

—Frontispiece 
"Oliver" Bandsaw, 82 
"Oliver" Handjointer, 36 
"Oliver" Trimmers, 97. 
Bed of Trimmer, 98. 
"Crane" Core Box machine, 45. 



PAGE 

Wood Lathe with Compound 

Rest, 54. 
Universal Sander, 29. 
Universal Bench Saw, 65. 
Williamsport Scroll Saw, 65. 
"Rogers" Double Surfacer, 153 



IN THE TEXT 



FIG. 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 
10. 
11. 
12. 
13. 
14. 
15. 
16. 
17. 
18. 
19. 
20. 

21. 



Cylinder, with coreprints, 6 
Holder's Flask, 7 
To illustrate "draft," 14 
Coefficients of shrinkage, 16 
Screws in end wood, 28 
Fillets sqr. corner, 31 
Fillets round corner, 31 
Pattern with square hole, 38 
Mold made from No. 8, 38 
Core and full box, 39 
Different size core prints, 41 
Taper core print system, 44 
(a) Section of a mold, 47 
Single flange wheel, 47 
Double flange wheel, 48 
Worm wheel, 48 
Hook lever, 49 
vSmall bracket, 50 
Loose pieces skewered on ,50 
Hollow cylindrical cast- 
ing, 51 
Hollow cylindrical pat- 
ern, 51 



Fig. 

22. Hollow cylindrical core- 

box, 52 

23. Built up disc, 56 

24. Built up disc edge, 56 

25. Thin board and counter 

ribs, 57 

26. Open joints cylinder hd., 58 

27. Open joints boxing up pat- 

ems, 58 

28. Open joints up corner, 58 

29. Lagged or staved up cyl- 

inder, 60 

30. Lagged up cylinder narrow 

lags, 61 

31. Lagged up core box, 61 

32. Annular pattern, 62 

33. Square frame (plate work), 

63 

34. Square frame (plate work), 

35. Round corner, 64 

36. Gland (the casting) , 67 

36. (a) Gland leaving its own 
core, 69 



ILLUSTRATIONS 



IX 



2>7. Gland Pattern, 67 

38. Gland core box, 71 

39. Laying out core box, 71 

40. Core box plane, 72 

41. Core box plane with guide. 

73 

41. (a) Conical core box, 74 

42. Chuck with pieces nailed 

on, 76 

43. Cylinder with flange both 

ends, 77 , 

44. Cylinder with flange both 

patterns, 17 

45. Cylinder with flange (core 

box), 77 

46. Pump standard (casting), 84 

47. Punipstandard(pattern) , 86 

48. Core prints for No. 47, 88 

49. Core box for No. 47, 89 

50. A, Turning bosses, 90 

50. B, Hook lever drawing, 91 

53. Pulley, 93 

54. Shoot board, 96 

55. Center of spider, 100 

56. Three armed chuck, 109 

56. A, Foim of gear rim, 110 

57. Methods of forming gear 

teeth, 112 

58. Box for laying out gear 

teeth, 113 

59. Laying out No. 58, 113 

60. Laying out tooth curves, 117 

61. Bevel gear lay out, 121 



62. Chuck, 122 

63. Chuck, large, 123 

64. Pipe bend, 126 

65. Pipe bend, 127 

66. Pipe bend, 127 

67. Pipe bend, 128 

68. Pipe bend, 128 

69. Pipe bend, 128 

70. Pipe bend, core box, 128 

71. Pipe bend, core box, 131 

72. Pipe elbow, 129 

73. Pipe elbow ring, 129 

74. Pipe elbow ends and 

prints, 130 

75. Pipe elbow built together, 

130 

76. Pipe elbow core box, 131 

77. Steam chest cover (cast- 

ing), 132 

78. Steam chest cover pattern, 
133 

79. Skeleton pattern, 134 

80. Skeleton pattern core, 134 

81. Skeleton pattern, boiler 

plate form, 136 

82. Gluing feather edge board, 

137 

83. Piston ring, 140 

84. Piston ring pattern, 140 

85. Drill press column, 141 

86. Loose piece dovetailed on, 

143 



Fig. 



APPKNDIX 

Fl G. 



1. Pattern-maker's bench, 167 

1. (a)Pattern-maker's vise, 168 

2. Bench hook, 168 



3. Saw-horse, 169 

4. Two-foot rule, 170 

5. Framing square, 171 



X 



ILLUSTRATIONS 



6. Tr3' square, 171 

7. Combination square, 172 

8. Bevel, 172 

9. Laying out angles with 

dividers, 173 

10. Marking guage, 174 

11. Mortise guage, 174 

12. Tanged firmer chisel, 175 

14. Socket firmer chisel, 175 

15. Inside gouge, 176 

16. Outside gouge, 176 

17. Sweeps of guages, 177 

18. Draw shave, 177 

19. Handsaw, 178 

20. Backsaw, 178 

21. Keyhold saw, 178 

22. Compass saw, 178 

23. Ripsaw teeth, 180 

24. Cross-cut teeth, 180 

25. Auger bit, 182 

26. Square hole auger, 182 

26. (a) Countersink drill bit, 

182 

27. Syracuse drill bit, 183 

28. Expansive bit, 183 

29. Forstner bit, 183 

30. Center bit, 183 

31. Countersink, 184 

32. Bit-brace, 185 ' 

^l. (a) Screwdriver, 185 

33. Miter box, 186 

34. Handscrew, 187 



35. Iron clamp, 187 

36. Iron plane with single iron, 

190 

37. Iron plane with double 

iron, 191 

38. Wood plane with double 

iron, 191 

39. Jackplane, 192 

40. Blockplane, 192 

41. Rebate plane, 193 

42. Plow plane, 193 

43. Dado plane, 194 

44. Spoke shave, 194 

45. Spoke shave, round, 195 . 

46. Grinding a cutting wedge, 

197 

47. Turning lathe, 200 

48. Fork center, 201 

49. Screw chuck, 202 

50. Cup chuck, 203 

51. Turner's gouge, 204 

52. Turner's chisel, 204 

53. Group of scrapers, 205 

54. Core box plane, 195 

55. Use of turning gouge, 206 . 

56. Use of turning or skew 

chisel, 207 

57. Use of turning chisel (two 
positions), 208 

58. Scraping a cylinder, 209 

59. Outside caliper, 210 

60. Inside caliper, 210 



CHAPTER I. 



INTRODUCTION 



A pattern may be defined as a model about which is 
to be formed a sand mold, in which a casting is to be 
made. It is usually of wood or metal, and often con- 
structed in several parts so as to facilitate removal from 
the mold. In the foundry and machinery business the 
word pattern is understood to mean any form or deviCC by 
the use of which a mold may be made. Pattern -making 
differs from all other wood-work in several ways. The 
product of the pattern shop becomes a part of the tools 
or working outfit of another workman, viz., the molder. 
The joiner, in making a door, makes it just the size 
required by the drawing or specifications; the cabinet- 
maker does the same when called upon to make a table 
or other piece of furniture; the carpenter also follows 
this same idea when building a bridge. In all these, the 
ultimate object is reached when the work is complete. 
It is not so, however, with the pattern-maker; his 
product is only one step in arriving at the desired end. 
that end being the production of one or more castings of 
some kind of metal. Allowances must be made in con- 
structing a pattern, that do not have to be considered 
in other wood -work; the principle of these allowances 
are for draft, shrinkage of the metal of the casting, and 
the machining of the casting where required. A pattern- 



2 WOOD PATTERN MAKING 

maker must be a good wood -worker, and able to work 
wood to accurate dimensions, both on the bench and in 
the lathe, as pattern -making consists largely of fitting, 
joining, and making circular and other forms to correct 
size. This knowledge and ability are necessary to the 
pattern-maker, because a large majority of patterns are 
made of wood. The pattern-maker must also know 
something, and the more the better, of the practical work 
of the molder. This is necessary in order that he may 
be able to produce easily-molded patterns. He should 
possess a good practical knowledge of the properties of 
metals, as, for instance, the contraction or shrinkage 
that these undergo in passing from the molten to the solid 
state, the strength of cast metals, and also their relative 
rate of cooling. He should also thoroughly understand 
the principles of Orthographic projection, so that, if it 
becomes necessary, as is frequently the case, he can 
make full sized working drawings of the work in hand. 
The production of ordinary metal castings, such as 
those of iron or brass, involves three distinct operations. 
First, making the pattern; Second, from this pattern a 
mold is made in sand or some other substance that is 
refractory enough to withstand the action of melted 
metal; Third, the metal is melted and poured into this 
mold. Each of these operations require especial skill, 
and has given rise to a special trade, although the 
second and third, called respectively molding and 
founding, are often performed by the same person. 
These operations are sometimes so intricate, and admit 
of so much variety, that the above statements are only 
true in the main. Nevertheless, they hold good in gen- 
eral, and in a consideration of this subject the pattern- 
maker may be understood to be a wood -worker, the 



INTRODUCTION 3 

molder as one that makes the molds, and the founder as 
the one that has charge of the furnace and the melting 
of metals. 

In the first of these operations, that of the pattern- 
maker, there is needed a fine degree of skill in the arts 
of cabinet making and wood turning. Moreover, the 
two trades, the molder's and pattern-maker's, are so 
intimately connected, that it is almost impossible to 
describe one without frequent reference to the other, and 
as a matter of fact there is almost as much to be learned 
of pattern -making in the foundry as in the pattern shop. 
So intimately connected are the operations of pattern - 
making and molding, that one of the chief qualifications 
of a good pattern-maker is the ability to form a rapid and 
reliable judgment as to the best way of molding a given 
pattern out of several ways possible. As there is usually 
more than one way of molding a given pattern, it is 
advisable that the pattern-maker, if in any doubt, confer 
with the molder as to his preference in the matter; as the 
molder is responsible for the production of the casting, 
he should have the pattern as he wants it. As pattern - 
making, therefore, is to be regarded primarily from the 
molder's standpoint, and not from that of the wood- 
worker, the following matters are of first importance: 

(l) Patterns being entirely enclosed in matrices of 
sand, provision must be made for pulling them out; this 
involves draught or taper, which is a thinning down of 
certain parts, division into sections, and provision for 
loosening by rapping. 

v2) Molding sand is always used damp, and pat- 
terns are subject to rough usage, consequently they 
must be made so as to resist any tendency to change 
their form and size from the absorption of moisture from 



4 WOOD PATTERN MAKING 

the damp sand, and they must be strongly constructed. 

(3) Most metals shrink or contract in passing 
from the molten to the solid state; therefore, patterns 
must be made larger than the required casting to allow for 
this. 

(4) Patterns may be entire or complete, exactly 
like the castings wanted ; however, if there are cavities 
to be formed in the casting, these hollow places will be 
represented by core prints. Moreover, the part 
the pattern-maker has to do with getting out a 
given casting may be the preparation of a sectional part 
or parts of a pattern from which only a part of the mold 
is made; the other partis made with a sweep, the boards 
for which are also prepared by the pattern-maker. 

(5) The practice of pattern -making is largely gov- 
erned by the requirements of the engineer; these require- 
ments are that patterns must correspond to drawings in 
all dimensions, that all centers be correctly located, and 
that all necessary allowances be made both for machin- 
ing and for the shrinkage of the metal of the casting. 

It will thus be seen that the pattern-maker has very 
little in common with carpenters, or indeed, with any 
other wood -worker, except for the fact that he uses the 
same tools and processes. To understand, then, the 
fundamental principles of pattern-making, it is necessary 
to master the principles of molding, and much of its 
details as well ; and to have a good working knowledge 
of modern machine shop practice. It is well to remember 
also that mere outside polish or finish on a pattern does 
not count for much if such matters as correct construc- 
tion and others already spoken of, are neglected. 

In many trades, to become an expert in handling 
tools, is the most neceesary requirement, but this is not 



INTRODUCTION 5 

the case in pattern -making, there being something far 
more important than cutting wood. In the construction 
of many patterns it is not so much a question of work- 
manship, as of knowledge. Certain patterns, for example, 
are very difficult to design, but after they are once made, 
they can be duplicated by any good wood -worker. In fact, 
it often requires but little skill to construct the necessary 
core boxes, etc., that may be required to produce certain 
castings. On the other hand, there is much pattern - 
making that calls for fine workmanship; in any event, 
pattern -making is not merely cutting wood. 

From what has been said, then, it will readily be 
appreciated that pattern -making is an important and 
responsible trade. For while the duty belongs to the 
draughtsman of preparing the design, yet the pattern- 
maker must be able so to interpret it as to get the idea 
the draughtsman intended to convey. Moreover, he 
must look forward to the requirements of the molder; 
consequently, from the drawing alone he must be able to 
imagine the completed casting, and build a pattern that 
will produce it. As the medium by which the designer's 
ideas are put into the tangible form of a casting, his, 
then, is a two-fold responsibility. Another fact that adds 
to his responsibility is, that there are so many different 
ways of molding. This gives a great field of study for 
the pattern-maker. The fact that there are so many dif- 
ferent ways of molding makes it advisable for the pattern- 
maker to consult the molder before making patterns for 
complicated work. 



CHAPTER II. 



MOLDING 



A pattern-maker should know something about the 
operations of the molder, so that he can make a particu- 
lar pattern of such a shape that it can be molded in the 
easiest way possible. This being the case, it is necessary 
to explain some of these operations. The form of pattern 
used in this illustration is what is known as a parted 
pattern; the molding operations that this form involves 
are generally few and simple. As will be seen by Fig. 1, 
the pattern is made in two parts, the parting or joint being 
along the axis of the cylinder. It is made in this way 




Fig. 1. 

for the convenience of the molder. These two parts are 
held sideways in relation to each other by what are called 
pattern pins, represented by dotted lines, c and d. Parts 
marked A and B are core prints, and will not appear on 
the casting. 

The appliance used by the molder in which to make 
the mold is called a flask, and is illustrated by Fig. 2. 
The upper part, A, is called the COpe, the lower part, B, 



MOI.DING 7 

the nowcl; C is the bottom board, D, cope bars, E, guide 

pins. Each flask is composed of at least these three main 
parts, viz., cope, nowel, and bottom board. Sometimes 
another part is introduced between the nowel and cope, 
called the clieck, or middle part. This is necessary when 
the casting is of such shape that its pattern cannot be 
taken from the mold with the one parting obtained by 
the use of cope and nowel alone, that is with the simple 
form of flask shown by Fig. 2. In addition to these 




Fig. 2. 

parts a molding board is needed, which may be just like 
the bottom board. Only one molding board is required 
by one workman for any number of flasks of the same 
size. 

The words top and bottom will be frequently used in 
writing of this flask. They refer to the flask when 
standing in what may be called its normal position, that 

is, as it stands when the mold is ready for the melted 

metal to be poured in. The relative position of these two 



8 WOOD PATTERN MAKING 

parts is that the cope is always on top, the nowel at the 
bottom. Each part is a box having neither top nor bot- 
tom, the sides generally being about 5 or 6 inches high, 
and rough inside. 

In order that, after being separated, these may be 
put together again in the same relative position, they are 
provided with guide pins (K) Fig. 2, the pins proper 
being on the cope, and the lugs into which they fit, being 
on the nowel. The cope is also provided with some 
form of handles. In Fig. 2, one of these is shown at E, 
being in this case a strip of wood about one inch square 
nailed across the end, directly above the guide pins. 
These handles are provided for the purpose of lifting the 
cope from the nowel at any time it becomes necessary to 
do so during the process of molding. 

There are also cross bars fastened across the cope 
(D Fig. 2) to assist in retaining the sand, which is held 
in place by friction only, the cope from necessity having 
no bottom. In all other respects cope and nowel are 
alike, except that in some cases one may be deeper than 
the other. 

In using this appliance the molder first places the 
molding board on the sand floor of the foundry in an 
approximately level position, and so it will not rock. 
He then places the half of the pattern that is without 
pins on its flat side in the center of the molding board. 
The nowel, or drag, which is the lower half of the 
flask, is next placed on this board, bottom side up, with 
the half pattern in the middle of it. Next he sifts 
-molding sand on to this board until the half pattern is 
covered to a depth of an inch or more ; he now shovels 
in sand until the nowel is filled and heaped up; then, 
with an implement called a rammer, he rams it down 



MOI.DING 9 

solid. The sand is now struck off even with the bottom 
of the nowel, some loose sand thrown on, and the bottom 
board placed on and rubbed around so as to make a solid 
bed for the body of sand in the nowel. Clamps are now 
put on so as to hold all together, the whole is turned 
over, the clamps removed, and the molding board lifted 
off. This completes one half of the mold, or, as the 
molder expresses it, "the nowel has been rammed up 
and turned over." He now sleeks the surface with his 
trowel until it is even with the flat surface of the half 
pattern, which is thus exposed to view, surrounded by 
sand. He now scatters on some parting sand, which is 
a very dry sand, usually burnt sand that has been cleaned 
from castings already made. The purpose of this is to 
prevent the next body of sand from sticking. The other 
half of the pattern is now laid on, its position being 
determined by the pins already spoken of, and the cor- 
responding holes in the other half of the pattern. The 
sprue pin or stick is now set up on the sand or parting 
just finished. This pin is a piece of wood, whose shape 
is the frustrum of a cone about ten inches long; its pur- 
pose is to make a hole through the cope sand into which 
the melted metal may be poured. Sand is put into the 
cope in the same way as was done with the nowel ; 
struck off even with the top, the sprue pin pulled out, 
and the whole surface brushed over so as to remove all 
loose sand. The cope is lifted off carefully, aqd set to 
one side. Both halves of the mold now appear exactly 
alike, except that the cope has the sprue hole running 
through it. 

The two halves of the pattern must now be drawn 
or pulled out. This the molder proceeds to do in the 
following manner: If the pattern is provided with lift- 



10 WOOD PATTKRN MAKING. 

ing plates, as all standard patterns should be, he intro- 
duces the end of the lifting screw into the hole provided 
for it in the lifting plate, and turns it in so that it is solid. 
If there are no lifting plates, he drives what he calls a 
draw spike into one of the halves. Then, with a mallet, 
a small hammer, or perhaps a sprue pin, he raps on all 
sides of the lifting screw or draw spike, so as to loosen 
the pattern. This operation, called rapping the pattern, 
enlarges the mold so that the pattern may be pulled or 
drawn out. This he now does, very slowly and care- 
fully, gently rapping the pattern until it is entirely free 
from the mold. This is done to both halves. A channel 
is now cut in the sand of the nowel from the spot on the 
parting where the sprue pin was set, to the mold or 
cavity left by removing the pattern. Thus is provided 
a passage through which the melted metal may run and 
fill the mold. This channel is called the gate. The 
mold is now ready to have the core set in. After the 
core is set, the cope is put back into its original or nor- 
mal position, which is determined by the guide pins; 
the whole is then clamped together, and set in position 
for pouring. As stated at the beginning, this process 
applies only to parted patterns. This same flask may be 
used in several different ways, the particular way being 
determined by the Shape and size of the pattern. For 
some shapes of patterns it is necessary to use three 
(3) boxes or partS; this is usually called a three-part flask, 
thereby meaning that the mold is composed of three dis- 
tinct bodies of sand. The central part of a three-part 
flask is called the cheek. The cheek has on it a set of 
guide pins the same as the cope, and also a set of lugs 
like those on the nowel, on the opposite edge. It is made 
in this way, so that any cope or nowel of the same size 
may be used with it. 



MOLDING 11 

These simple explanations will be enough to give 
the student of pattern -making a general idea as to the use 
of patterns in the foundry. Of course there are many- 
details to be observed and carried out in the production 
of castings that are not mentioned above, but as these 
more particularly concern the molder than the pattern- 
maker, they will not be noticed here. 



CHAPTER III. 



GENERAL PRINCIPLES 



In building foundry patterns several ideas must be 
be kept in mind, either consciously or unconsciously. 
These are four in number, or (.when we have no source 
of information as to what is wanted, except a drawing of 
the required casting), there may be five, as follows: 

(1) What may be called the designer's idea; (2) the 
way in which the pattern is to be pulled from the sand ; 
(3) the draft, or taper,' which is a thinning down of cer- 
tain parts of the pattern in order to facilitate its removal 
from the mold or sand; (4) the SlirinRage of the metal of 
the proposed casting, while passing from the molten to 
the solid state; and (5) the machining or finishing of the 
casting after it is made or cast. 

An experienced pattern -maker may not be conscious 
that he has in mind any one of these ideas, because he 
uses them so frequently that he does so without thinking 
especially of them; in other words, they become second 
nature to him. It is these last four ideas, among others, 
that separates this trade from all other wood -working 
trades and connect it with the engineering profession, for 
there is not one of them that has even to be thought of by 
those working at any other of the wood -working trades. 
Before we explain these ideas in detail, it will be best to 
have them arranged before the mind in such a wav that 



GENKRAL PRINCIPLES 13 

they may be easily remembered, and in the order of their 
use and importance. For convenience, then, we will put 
them in a vertical column, thus: 

1. Designer's idea. 

2. Way to be drawn from mold. 

3. Draft. 

4. Slirinkage of metal. 

5. Macliining. 

Besides these five ideas, the last three of which may 
be called allowances, there are two other allowances that 
sometimes have to be considered, viz. : for shake and for 

warp. 

The two first of these five are purely abstract ideas. 
If it is desired to make a pattern from a drawing only, 
that is, if there is no other means of knowing what is 
wanted, then it will be necessary for the one building it 
to form as nearly as possible the same mental picture 
that the designer had in mind when making the drawing. 
This may be called the designer's idea, md to some 
extent, at least, must be realized before much can be 
done towards building a pattern. After having thus 
formed in mind the general shape and approximate size 
of the required pattern, it can be decided in which way 
it shall be drawn from the mold. This must be decided 
before very much can be done towards building the pat- 
tern, so that the draft may be made in the right direc- 
tion, which is a very important matter. 

The other three points that were mentioned are 
sometimes spoken of as the allowances to be made in 
pattern -making. They are really additions made to the 
size of the pattern in some one direction, or, as in the 
case of shrinkage, in all directions. The first of these, 
and in some respects the most important, is what 



14 



WOOD PATTERN MAKING 



is technically called draft. This is a thinning down 
of certain parts of the pattern; that is, the vertical sides 
of the pattern are tapered, and it is sometimes spoken of 

as the taper. 

The amount of draft to be allowed is governed by 
the case in hand, some patterns requiring more than 
others. The usual amount is 1-8 inch for 1 ft. in 
height; this is generally enough for small and compara- 
tively plain work, but for complicated work it is not 
enough. No hard and fast rule, however, can be given 
for this allowance, or indeed for any work in pattern - 
making. What is nearest to a general rule may be 




Fig 



stated thus : Give the pattern as much draft up to 1-4 

Inch per foot in height as will not Interfere with the design. 

Whatever amount is allowed should be added to the 
size of the casting as given in the drawing. For small 
and plain work one -sixteenth of an inch will be enough, 
but if the pattern is at all complicated, one -quarter of an 
inch will not be too much. Of course, the requirements 
of the molder have to be considered, and if he was asked 
about it he would always say, give it the larger amount. To 
make this more plain, we will suppose that a pattern was 
wanted from which to make a mold for the casting rep- 
resented by Fig. 3. 



GENERAL PRINCIPLES 15 

Now applying the above principle, we should make 
the top longer and wider by % inch than the size given, 
so that the top of the pattern would be S}i inches long 
and 6% inches wide. This addition, or allowance is 
shown by the dotted lines. In this case the pattern 
would be drawn out of the mold in the direction of the 
arrow. In practice it would not be necessary to allow 
so much draft on as plain a pattern as this, but we use it 
as an illustration of what is meant by the term draft. 
All vertical sides of the pattern, whatever its shape, must 
have some taper in order that the molder may get it out of 
the mold without breaking the mold. If no draft is 
allowed, the molder has to rap the pattern so much that 
the mold will be distorted and the casting will not be 
like the pattern. 

The next important principle to be observed, especi- 
ally when the casting is required to be exact in size, is 
that relating to Shrinkage. Whenever this word is used 
in connection with pattern making, it always means the 
shrinkage or contraction of the metal of which the cast- 
ing is made. An iron, brass, or steel casting is always 
smaller than the mold in which it was made, and this is 
true also of castings made of any of the other metals in 
common use. This is due to the shrinkage of the metal 
when cooling. The amount of the shrinkage varies in 
the different metals, and also in the same metal under 
varying conditions. Brass will shrink more than iron, 
and iron that is very hot when it is poured into the mold, 
will shrink more than iron that is comparatively cool 
when poured. The size and the shape of the casting also 
have much to do with the amount of shrinkage. An 
iron that will shrink one-eighth of an inch to the foot in 
light work, will shrink only one-tenth of an inch, or less. 



16 



WOOD PATTERN MAKING 



in large work. For instance, in casting large box or 
cylindrical -shaped castings, one-tenth of an inch per 
foot is usually enough to allow for this shrinkage in the 
diameter, but one-eighth ot an inch will not be too much 
in the length. The reason for this difference is due to 
the fact that the castings are practically unrestrained in 
their length, and are comparatively free to shrink in this 
direction, while in the diameter they are restricted by 
the cores and internal parts of the mold. The amount 
of allowance usually made in common practice is 1-8 inch 
per foot, measured in all directions. But since the 
coefficient of shrinkage is different for different metals, 
this is only approximate. The following allowances for 
the different metals are made in the pattern when it is 
surely known just what metal the casting is to be made 
of, as, of course, is the case usually. One good way to 
remember these is to arrange the figures that represent 
these amounts in a group like Fig. 4. 




Fig. 4. 



then, this allowance is 

1/ 



i,< 



'/lO 



inch ; 



for 

I/' 



For iron, 
brass, Wie inch; aluminum, }{ inch, and for steel, 74 
inch; the general amount, which is in the center of the 
group, is /8 inch. It must not be understood by this 
that these metals will always, and under all conditions. 



GENERAL PRINCIPLES 17 

shrink just these amounts; for, as has already been men- 
tioned in the case of iron, the amount of shrinkage varies 
somewhat under varying" conditions. For the use of 
pattern-makers, scales or rules are made. The one 
most commonly used provides for an allowance of }i 
inch per foot; that is, the rule is made ^8 inch longer 
than the standard foot rule, and each "inch" is cor- 
respondingly longer on it than the standard inch. Scales 
or rules can be bought at dealers, graduated for the other 
shrinkages above spoken of. 

It has been a mooted question as to just when this 
shrinkage or contraction takes place in the casting, but 
it is generally conceded now that it takes place in passing 
from the plastic condition to the solid state. All metals, 
in passing from the liquid to the solid state, suffer 
expansion when in the plastic condition. It is this 
feature in the transition that enables metals to take and 
retain the impressions of the molds with such fidelity. 
Allowance for shrinkage is not regarded on patterns that 
are Six inches or leSS in area, as the rapping of the pattern 
will usually make up for any shrinkage that may take 
place. Patterns that are four inches or ICSS in size, are 
made slightly smaller than the desired size of the cast- 
ing. This is called an allowance for shake. It is not 
regarded unless it is necessary that the casting be exact 
in size. Patterns between six and four inches may be 
made without regarding either shrink or shake. 

In building machinery it is often necessary to fit two 
castings together. Wherever this is done, the two sur- 
faces that come into direct contact are usually machined 
in someway in order to obtain a smooth, clean surface 
of metal. A part of a pattern that represents a surface 
of this kind on the casting, must be made larger. This is 



18 WOOD PATTERN MAKING 

the case, whether the two surfaces are to slide or rotate 
on each other, or whether one is simply bolted to the 
other. It is called an allowance for machining or finish. The 
amount of this allowance is generally /i inch, measured 
perpendicular to the surface to be machined or finished. 
If the surface is simply to be machined to fit another sur- 
face, and the work is comparatively small, this will be 
enough. But if it is required to have a very nice finish, 
free from all sand holes, or if the work is large, it might 
not be enough ; in some cases it might be necessary to 
make it twice the amount, or }{ inch on each surface. 
Moreover, as the casting increases in size, its irregulari- 
ties also increase, so that a larger amount must be 
allowed. In the case of large work, such as engine beds, 
the allowance is frequently made from % to 1 inch. A 
large allowance is especially necessary on very irregular 
and new work, as the amount of distortion caused by the 
strains set up in the casting by shrinkage is very uncertain. 
I^arge steel castings are usually very rough, and also 
become more or less distorted in cooling and anneal- 
ing, so that it is necessary to allow more on this account. 
Of course, the exact amount must be determined by the 
circumstances of any given casting, but there should be 
enough so that in taking the first cut, the tool used may 
get beneath the sandy scale that is always present on a 
casting, and still leave enough for a second cut at least, 
and a third or finishing cut if necessary. It, therefore, 
cannot be much less than one-eighth of an inch. 

There is one other allowance to be mentioned that is 
not usually called for in making machinery patterns, but 
is frequently in making what are called architectural 
patterns. Some castings, because of their varying thick- 
ness, or because of one surface being more exposed than 



GENKRAI. PRINCIPI.es 19 

another, therefore cool more rapidly, warp or become 
distorted in the mold when cooling. To overcome this, 
patterns for castings of shapes that are known thus to 
warp, are made of such a shape that in cooling they will 
assume the desired shape. This change in shape of 
patterns is called an allowance for "warp." 



CHAPTER IV. 



MATERIALS 



Wood is the material used for a large majority of 
patterns. At first thought it would seem that wood is 
a particularly unsuitable material to be used in matrices 
of damp sand, and to be subject to such rough usage as 
the ramming and rapping of a pattern necessarily 
involves, but there are several reasons why wood is used. 
The first that may be mentioned is that it is easily worked 
and altered. Secondly, it is light and portable. Further- 
more, by exercising due care in construction, its dis- 
advantages may in a degree be overcome. The pattern- 
maker, of course, meets with the same difficulties with 
which other wood -workers have to contend, and as inter- 
fere with the durability of patterns. The chief one 
among these is due to the tendency of wood to shrink 
and swell, which cause warping and change in form and 
size. This cannot be wholly overcome, but by arranging 
the different pieces in a given pattern with a due regard 
for this natural tendency, it may to a degree be counter- 
acted. To prevent warping it is necessary to know the 
effect this tendency has upon the individual board ; and 
this may be determined, if the position of the board in 
the log is known, which may be determined by examin- 
ing the end. If a board is cut from the middle of, and 
directly through the diameter of the log, it is not very 



MATERIALS 21 

likely to warp; but if a board is cut from a position mid- 
way between the heart and the outside of the log, it is 
sure to do so, for it will assume a curved outline between 
the edges, the heart side always becoming convex. This 
is caused by the more rapid drying of the board on the 
sap side. For as the board is cut through the concentric 
cylindrical layers of which the log is composed, the 
outer side of the board contains more exposed fibre ends 
and more open pores than the heart side. Consequently, 
the sap side of a board gives off the moisture it contains 
more rapidly, and it will also absorb moisture more 
rapidly. In view of this fact, the sap side of any board 
should be placed where it will be the least likely to be 
exposed to any change in atmospheric conditions. That 
is, whenever it is possible, this side of the board should 
be always placed on the inside of any pattern work. 

What is known as quartcr-sawn lumber is the 
best for pattern -work and all wood-work, because it is 
not so likely to warp as is the regular, or bastard -sawn. 
Quarter-sawn lumber is lumber that is sawn approxi- 
mately parallel with the medullary ray. The trunk of a 
tree is made up of concentric cylindrical layers, bound 
together with radial fibres, which are known as medul- 
lary rays. It is the exposure of these rays that gives to 
quartered oak the beauty that is so much prized. How- 
ever, quartering is a very wasteful way of sawing lumber, 
and involves an extra cost. But for pattern work that 
must be made thin, it pays to use quarter-sawn lumber, 
even if it does cost more. 

Another very important factor in connection with 
lumber for patterns is, that it should be thoroughly 
seasoned before being used, if possible, by what is known 
as the natural or air seasoning process. The seasoning 



22 WOOD PATTERN MAKING 

should continue for at least tWO years, in order that the 
natural gums of the wood may be fixed ; that the rapid 
drying of the kiln will not drive them out and in that 
way make the wood more porous. Lumber intended for 
pattern work, if allowed to remain in a shed with a 
waterproof roof for two years, will give better results 
than lumber exposed to all sorts of weather for six 
months, and then placed in a dry kiln to finish the pro- 
cess. For one-inch lumber two years is enough; thick- 
er planks will, of course, need more time, say four 
years for two- inch. However, lumber cannot be so 
thoroughly seasoned as to give entire permanence of 
form and durability to patterns made from it. 

Besides being thoroughly seasoned, lumber for 

patterns should be Straight, and evcn in grain, 

not too hard to be easily worked, yet not so soft 
as to be unduly injured by the rough usage 
patterns must necessarily undergo in the foundry. 
There is no wood that fulfills these conditions better 
than what is known as White Pine (Pinus Strobus), 
sometimes called "cork pine" because of the cork-like 
appearance of the bark. This wood, when thoroughly 
seasoned, will retain its shape very admirably under the 
excessive atmospheric changes that patterns have to 
undergo from pattern-shop to foundry, and from foun- 
dry to the storage loft. When first cost need not be 
considered, and it should not be in the case of small 
standard patterns. Mahogany, what is known in the 
market as Honduras M., is the best wood for all patterns; 
it is very even and straight in the grain, not so hard but 
that it can be easily worked, and retains its form and 
size to a remarkable degree. One thing to be men- 
tioned in this connection is the arranging or 



MATKRIAI.S 23 

combining the several pieces of which a pattern is made in 
such a way that any shrinking or swelling of the wood 
shall not change the shape or size of the pattern. This 
is an important matter in some classes of work, and 
should have the careful consideration of the pattern- 
maker, especially in the case of standard patterns. If 
this is done it will add considerably to the durability of 
a pattern. 

There is one principle it is well to observe in combin- 
ing the several pieces of wood in a pattern, and that is 
to have as near as possible the grain of the wood run in 
the same general direction, so that as it shrinks or 
swells it will do so in the same direction, and there- 
fore will not distort the pattern. 

Special patterns are often made of braSS, iron, whitC 
metal or alumnium. These metals would be used in light 
or curved work, and also when a large number of cast- 
ings of the same size and shape are wanted. With few 
exceptions, however, original patterns are made of wood. 
Statuary and other ornamental work is usually modeled 
in wax or clay, which serves as the pattern. When it is 
proposed to use a metal pattern for the production of 
castings, the original pattern is made of wood and is called 
a master pattern or double -ShrinRage pattern. This is 
made with a double -ShrinKage allowance, so that a casting 
made from it will still be large enough for the pattern 
from which to make the castings wanted. Patterns made 
of wood must be varnished or they will soon go to pieces. 

SANDPAPER 

In pattern work sandpaper should be used with dis- 
cretion. The pattern should be formed as nearly to shape 
and size and finished as accurately as possible with the 



24 WOOD PATTERN MAKING 

cutting tools before sandpaper is used. Under no cir- 
cumstances should sandpaper be used for cutting down 
or removing any considerable amount of stock, or for 
doing anything that can be done with tools. Otherwise 
the draft and the accuracy may be impaired. Sandpaper, 
as its name implies, is made of sharp sand (Quartz or 
Garnet) glued on paper. It is graded according to the 
grains of sand, and numbered accordingly. The grades 
most useful to the pattern-maker are Nos. 0-2. No. ij 
is best for use directly on the wood, and No. 1 for the 
varnished surface. Ordinarily, sandpaper should be 
rubbed across the grain of the wood. In the last two or 
three years, what are called pattern -grinding or sanding 
machines have been introduced to the trade to take the 
place, in some kinds of work, of sandpapering by hand, 
and they accomplish the work much better and more 
rapidly. Any kind of abrasive that can be fastened to 
the machine may be used. 

GLUE 

In pattern -making as in most of the wood -working 
trades, glue is depended on for adhesive fastening. For 
fastening leather fillets, shellac varnish is sometimes 
used. Since much depends on the character of the glue 
used, it should be of the best. There are many kinds 
and qualities of glue on the market, including liquid, 
pulverized or ground, and sheet. The liquid glue is 
always ready for use and is very good for small work. 
The sheet or flake form, ground, dissolved and applied 
hot is the best for general use. Animal glue comes in 
thin sheets; it is the best, and likewise the most expen- 
sive. Of late years the large manufacturers of glue have 
taken up the practice of grinding these sheets, which 



MATERIALS 25 

makes it much handier for use. However, this enables 
dishonest dealers to g:rind the cheaper kinds of glue and 
pass them off as the best, for when ground it requires an 
expert to tell the difference, but when it is cooked, the 
odor given off will generally indicate its quality. As a 
rule, the best quality of glue is of an amber color, and 
the sheets rather thin. Whichever kind (excepting of 
course the liquid) is used, it should be soaked in cold 
water for a short time before cooking; only a small quan- 
tity should be prepared unless the shop is provided with 
a steam glue heater that is kept hot. Glue is much 
stronger if used while fresh, as frequent heating and 
cooling destroys its strength. To obtain the best and 
strongest joint, the wood should be slightly warmed too, 
say from 90 to 120 degrees, and the glue applied as hot 
as possible, and the work quickly clamped. As a rule, 
the harder the glue the better it will resist moisture. 
When it is necessary to glue two pieces of wood together 
so that the joint is on the end grain, the end should first 
be given a coat of thin glue, which should be allowed to 
dry before applying the glue for the joint. This is called 
sizing the joint. Plenty of time should be given the joint 
to dry — ten to twelve hours, according to the size of the 
work, will usually be enough if in a warm and dry shop 
or room. To much care cannot be exercised in the use 
of glue for pattern work, indeed it is not advisable to use 
it at all when nails or screws will answer the purpose. 
But there are some kinds of patterns that cannot be made 
without it. 

VARNISH 

All wooden patterns should be covered with some 
kind of protective coating so as to prevent as much as 
possible the absorption of moisture from the damp sand 



26 WOOD PATTERN MAKING 

of the mold, for this is very injurious to all wood work. 
The protective coating should be of such a nature as to 
be unaffected by RlOisturC and also to insurc a hard, SmOOth 
surface that will "draw" easily from the mold. 

In practice there are two general classes of varnishes, 
Shellac and Copal. The first, which is the kind most 
generally employed, is composed of common Gum Shel- 
lac cut with alcohol and colored, if so wanted, with some 
kind of coloring ingredient. The second comprises the 
better grades of Copal varnishes used by finishers. This 
may also be colored. By changing the color of the var- 
nish employed, it is possible to distinguish between core 
prints and the body of the pattern, and also between 
patterns for castings of different metals, such as brass, 
iron and steel. 

For shellac varnish a good grade of gum should be 
used as the cheaper grades will not stand up to the 
work. This is usually called ycllOW varnish. BlacK 
varnish is made by adding lampblack; a good quality of 
lampblack should be use, one that is free from grit. 
Red varnish is made by adding some red powder, usually 
Indian red, or Vermillion (Chinese is best) to the yellow 
varnish. The use of these in varnish seems to give it a 
better body and greater durability. Copal varnish, how- 
ever, is still more durable, and if time (about three days) 
can be given it to dry, it is much the better and will out- 
last several coats of shellac varnish. 

BKKSWAX 

Beeswax is used for making small fillets, and filling 
small holes, such as nail holes, etc., and any other slight 
defect in either material or workmanship. It may also 
be employed for making a slight change in the form of 



MATERIAI^S 27 

a pattern that is not much used. It is not good practice, 
however, to use it in this way on standard patterns, as 
it is very liable to melt and run out in the storage loft 
during warm weather. 

Wax is sometimes used for coating iron patterns to 
prevent them from rusting. To cover iron patterns with 
wax, they should first be made as warm as they can be 
handled, then the wax should be spread on them as 
evenly as possible and brushed over with a soft brush. 

NAII,S 

For pattern work, what are known as "wire brads" 
are the best nails. They can be driven almost anywhere 
in the wood without splitting it. They may be had of 
all lengths from one-half inch to three inches and of 
different sizes of wire. However, owing to the necessity 
of rapping patterns when drawing them from the mold, 
it is always best to use screws when fastening the differ- 
ent parts of a pattern together. They are much better 
than nails on account of the clamping effect they give to 
the pieces to be joined. This is a very desirable effect 
in the case of standard patterns. Another reason why 
screws are much better than nails for this purpose is that 
when it is necessary to change or repair a pattern, screws 
can be taken out without tearing the wood of the pattern, 
and if needed, can be replaced exactly in the same place. 
Screws are also handy for temporarily securing loose 
parts of a pattern, and for this use are much superior to 
nails or pins, When screws are to be used for fastening 
two pieces of wood together, holes as near the size of 
shank of screw as possible should be bored through the 
upper piece. If this is not done the screw will cut a 
thread in both pieces thus hindering the clamping effect 



28 



WOOD PATTERN MAKING 



that is Otherwise obtained by the use of screws for this 
purpose. 

As is well known to most wood -workers, end grain 
wood, especially soft wood, does not hold a screw very 
securely, unless some special method is used. One of 
the best ways of putting screws into end grain is to bore 
a hole of a size as near as can be to the size of the solid 
part of the screw. The thread of the screw will then 
cut its way into the wood without disturbing the fiber 
and thus the full shearing strength of the wood will serve 
to hold the strain put upon the screw. The hold of a 
screw in end wood may be increased by taking it out, 
placing a small amount of glue in the hole, and putting 
the screw back in at once while the glue is soft. It is 




Fig. 5. 

sometimes necessary to take out and reinsert screws in 
end wood, repeatedly, — for instance, when pattern work 
has to be taken apart for convenience in molding. In 
such cases, simply screwing them into the end wood 
should not be depended upon, as they get loose and do 
not hold. A good way to overcome this difficulty is 
illustrated by Fig. 5. It is to bore a hole at right angles 
to the direction of the screw in such a position that the 
screw shall pass through it; fill this hole with a hardwood 



MATERIAI.S 



29 



plug, bore a hole of suitable size for the screw and insert 
the screw. If now the screw from frequent taking out 
and screwing in becomes loose, the plug may be taken 
out and another put in its place. As noted elsewhere, 
screws make a much stronger fastening than nails and 
should always be employed in pattern work that is to be 
much used, as in the case of a standard pattern. 




Clement Universal Sander 



CHAPTER V. 



FILLETS 



Sharp corners on a casting, whether inside or out- 
side, generally detract greatly from its appearance, and 
also, in the case of internal angles especially, injure its 
strength. This being the case, sharp corners must be 
avoided in the pattern, as the casting will be of the same 
shape as the pattern. The weakness due to sharp cor- 
ners, especially in the case of internal angles, is caused 
by the way iron acts in cooling, or in passing from the 





Fig. 6. 



Fig. 7. 



molten to the solid state. There are always more or less 
strains set up in a casting by the shrinkage or contrac- 
tion that takes place at that time. As the iron hardens 
the crystals seem to arrange themselves in such a man- 
er that their lines of strength are perpendicular to the 



FII,I,KTS 



31 



faces of the casting. For instance, in a casting of the 
general shape shown by Fig. 6, these lines arrange them- 
selves as shown by the short lines drawn perpendicular 
to each face and thus leave the space (a) open or honey- 
combed, consequently the casting will be very weak 
through the line (be), and when a strain is put upon it, 
it will be likely to break. In some shapes of castings 
these strains caused by shrinkage will of themselves 
crack the casting at this point and at all similar sharp 
internal angles. If the above casting is made with a 
fillet or rounded -in angle, this is not so likely to be the 
case, and if it is made as represented by Fig. 5 it will be 
just as strong at that point as at any other. For, as will 
be noticed, there is no place for this irregular crystalli- 
zation to take place. In view of these well-known facts, 
all internal angles should be thus rounded in or "filleted" 
on the pattern. 




There is another advantage gained in thus rounding 
in these internal angles that is appreciated by the molder. 
In molding a pattern of the general shape of Fig. 7(a), that 
for some reason has to be pulled or drawn from the mold 
in the direction of the arrow, a very sharp corner of sand 



32 WOOD PATTERN MAKING 

will be left at the point (c). As the pattern is pulled up 
by it, a slight movement of the pattern sidewise would 
break it; then as soon as the pattern became clear of the 
mold, the sand would fall down into it, thus making 
what the molder would call a dirty mold. It would cause 
him some trouble to remove this sand from the mold, 
and it must be all cleaned out, for otherwise it would 
surely make a poor spot on the casting and might render 
it unfit for the use to which it was intended to be put. 
Therefore, for the molder's benefit as well as to strengthen 
the casting, it is best to round in any internal angles. 
Fillets may be made of wood, wax or leather. The last 
is undoubtedly the best; it also is the most expensive, 
at least in its first cost. Wood is generally used for 
straight work, the best practice being to fit and glue a 
piece of wood of the right size into the angle and allow 
it to dry before cutting the required curve. By work- 
ing the curve after it is glued in place, the tendency of 
thin edges of wood to curl when made wet, which of 
course is done in the glueing, is entirely overcome. There 
is no objection to using wood for this purpose if the wood 
that is used is straight in grain, and if the grain of the 
wood of which the fillet is made lies in the same direc- 
tion as the grain of the wood composing the part of the 
pattern to which it is glued. Leather is the best material 
of which to make fillets, since it is elastic enough to 
come and go with the wood as it shrinks and swells. It 
is as permanent as the pattern itself, gives a very smooth 
finish, and is easily applied. Wax is not very good 
except for very small fillets or for temporary patterns. 
It should not be used for fillets on standard pattern 
work as it is likely to melt and run out when exposed 
to summer heat in the storage loft. 



FILIvKTS 



33 



In making and applying fillets of wood, the process 
is something like this : First, a piece of wood of the 
proper length is ripped out square, so that each side is 
equal to the radius of the curve of the proposed fillet. 
One corner is fitted to the angle proposed to be filleted ; 
it is better if this does not exactly fit clear into the angle, 
that is, the fillet piece may be a little loose at the apex 
of the angle but should fit tightly on the other two sides 
of the triangle. When this is properly fitted the remain- 
ing or outside angle may be planed off with the jack 
plane so as to make a triangular- shaped piece. The 
third side, the one last made, is a good place in which 
to drive brads for holding the piece in place while the 
glue is drying. The brads should be placed about four 
inches apart. When a sufficient number of brads have 
been started, the glue may be applied to the piece, the 
piece set into the angle and the brads driven in as far as 




Fig. 6 (a) 

can be, while still leaving the heads protruding, so that 
they may be pulled out when the glue is dry. When the 
glue is thoroughly dry the nails may be pulled out, and 



34 WOOD PATTERN MAKING 

the required curve cut or worked with gouge and sand- 
paper, making it as nearly tangent as possible to the 
two sides it connects. This work is illustrated by Fig. 
6 (a). In order to apply leather fillets successfully, a 
tool known as a "filleting tool" is needed. It consists 
of a sphere of iron, or, still better, of brass, fastened to a 
short rod somewhat smaller than the sphere. The 
diameter of the sphere should be equal to that of the 
fillet. After the leather fillet is cut to the required 
length, moderately thick, clean glue, not too hot, is 
applied; the leather is placed in the angle, and the fillet- 
ing tool is run along the angle, pressing the leather 
firmly into place. The pressing should be done heavily 
enough to squeeze out all surplus glue, which should be 
cleaned off at OnCC with a piece of cloth or waste 
dampened with hot water; then the surface thus made 
wet should be wiped as dry as possible with a dry piece 
of the same material. The filleting tool should be quite 
warm for this operation. 

Wax fillets are put in in the following man- 
ner: Some wax is softened by heat and rolled into a 
omall cylinder, the diameter of which is governed by the 
size of the fillet. It is then laid in the angle. The fillet- 
ing tool before mentioned is warmed enough to soften 
the wax, and the cylinder is pressed into the angle. The 
wax, being softened, conforms to the shape of the tool, 
which, as it is passed along, leaves a circular surface 
tangent to the two sides of the angle The surplus wax 
should be cleaned off up to the line made by the tool. This 
makes a very nice job, and is a good way of making 
fillets for patterns that are not to be much used. There 
are on the market small presses that turn out cylinders 
of wax for making wax fillets. They are so arrange 



FILI.ETS 35 

that different sizes of cylinders are made for different 
sizes of fillets. These small cylinders of wax are also 
used for venting cores and molds. These machines save 
considerable time and trouble in this kind of work, and 
also do it more satisfactorily. 



CHAPTER VI. 



CORKS. 



When castings with holes through them, or 
with internal cavities, are to be made, a pro- 
jecting body of sand must either be made in the 
mold at the same time as the rest of the mold, or else be 
introduced into the mold after the pattern is removed or 
pulled out. These projecting bodies of sand are called 
cores. When the pattern can be withdrawn from the mold 




Fig. 8. Fig. 9. 

and leave a core, or cores, as a part of the mold, it is said 
to leave its own core or cores. This is illustrated by Figs. 
8 and 9. Fig. 8 represents a pattern that has been 
molded and removed from the mold; (Fig. 9) leaving 
core (a) projecting above the lower surface of the mold. 
When the cope is closed^'the'^'cope sand will, of course, 



38 WOOD PATTERN MAKING 

touch the upper surface of these cores ; when the mold is 
filled with melted metal, it cannot get where these cores 
are. The result is that the casting will have a 
hole through it the shape of the core (a). Where pat- 
terns cannot be so made and molded with the ordinary 
appliances of the foundry to form their own cores, there 
is added to the pattern an attachment or projection that 
forms a mold in the sand, into which a separate core may 
be placed. These attachments are called COrc prints. 

These cores that are made separate from the mold 
are usually what are called dry Sand cores, although 
^rcen sand cores are sometimes made in the same way. 
A simple form of pattern for a mold with a dry sand core, 
is represented by Fig. 1, parts A and B being core 
prints. 

A dry sand core is made in a separate device 
called a COFC boX. In the case of a symmetrical core, a 
core box is made only for a small portion of it. For a 
cylindrical core only a half box need be made; two 
cores from such a box be pasted together, thus form- 
ing a complete core. This same principle may be used 
in the case of very large work. A symmetrical mold, 
like one for a fly wheel, may be built up almost entirely 
with cores. 

Core boxes require as great care in their manufac- 
ture as patterns, and as much thought must be given to 
their shape, durability and finish. The shape of a pattern 
is nearly like the required casting; but the inside of the 
core box, which is, of course, the necessary part, is just 
the reverse, resembling more nearly the shape of the 
mold. When cores are made in boxes and inserted in 
the mold, it is necessary that they be supported in such a 
way that there will be no chance for a change of position 



CORES 



39 



during the time the mold is being filled with the molten 
metal. To give this support, special recesses are made 
in the mold to receive them. These recesses are made by 
the core prints previously mentioned. The core should 
exactly fill the recesses left by the core prints, and this 
part of the core should be large enough to support the 
core properly in place, so that the sand of the mold will 
not be crushed out of shape by the weight of the core, 
nor by the action of the metal while being poured into 
the mold. 

Core prints should be given more taper than the 
pattern itself, so that the work of withdrawing the pattern 
from the mold may not be unduly increased by 
their presence, and also so that the core may be the 
more easily adjusted to its proper position. In the case 
of plain cylindrical cores, whose length does not exceec" 




Fig. 10. 

five times their diameter, or of such as may be stood on 
end while drying, a full box may be constructed and the 
cores made whole. This, of course, saves the time of 
the core-maker, as he does not have to cement the two 
halves together. A core made in this way, with its box, 
or mold, is represented by Fig. 10. In making these 
core boxes and core prints, care should be taken that the 



40 WOOD PATTERN MAKING 

part of the box corresponding to the print on the pattern 
should be exactly the same size and shape as that print, so 
that when the core is set into the mold it shall exactly fit. 

All core prints should be of ample size, so that their 
impression will hold the cores in their place, and so 
that the weight of the core and the weight and action of 
the melted metal will not change the position of them. 
It is well to remember that the material that must do 
this holding is only loam, or, as it is technically called, 
"sand. ' ' It therefore requires a comparatively large sur- 
face to make them secure against the weight and action 
of melted metal during the process of pouring it into the 
mold. On account of the varying shapes and conditions 
there can be no exact rule given for the sizes of these 
prints, that will cover all cases. The length of the core 
prints for a plain cylindrical horizontal core should 
approximate its diameter, and its shape should be that of 
a cylinder. For a VCrtlcal core of this same general 
shape, the print should be the frUStrum Of a COnC, with the 
large end next the pattern; the height should be Onc 
inch, and the diameter of the small end onc-half inch ICSS 
than the large end. 

In core work that requires prints of other shapes 
than those mentioned above, that is, where the opening 
into or through the casting is not round, then the prints 
should correspond in shape. 

The making of core prints properly located and of 
correct size and shape is a very important part of the 
pattern-maker's art, especially so from the molder's 
standpoint. Prints that do not show the exact position 
of the core may be very misleading and may result in the 
loss of the casting. One form of core where this mistake 
might easily be made and not be noticed until the cast- 



CORES 



41 



ing: was formed is illustrated by Fig. 11. The figure 
represents a casting that requires a cylindrical horizontal 
core with a part enlarged to make the cavity (A) which, 
it will be noticed, is not in the center of the 
length of the casting. In this case if both core prints 
are made of the same size, the molder will be quite likely 
to set the core wrong end to. The molder would not be 
altogether to blame for this mistake as he generally does 
not have anything to guide him in this work except the 
pattern and core box furnished by the pattern-maker. 



I 




Fig. 11. 

But if one core- print is made larger than the other, then 
it will be impossible for him to set it incorrectly without 
deliberately cutting the mold. In all core work, there- 
fore, the prints should be of such size and shape that it 
will be impossible to set the core into the mold in any 
other than the correct way. As mentioned above, one 
method is, as shown in Fig. 11, to make one print larger 
than the other or of a different shape. For cylindrical 



42 WOOD PATTERN MAKING 

cores, the first is of course the best, and is sure to accom- 
plish the desired result. Sometimes it is required that 
a cylindrical core should lie in the mold in a certain 
position with regard to its circumference. In that case 
it would be necessary to change the shape of at least one 
of the prints, making one or both square so that the core 
cannot be set wrong or revolve after being set. 

Some prints for horizontal cores are not made long 
enough, consequently the metal when poured into the 
mold will, by its own static pressure, raise or displace 
the core and make the casting thinner on the cope side 
because of this movement. 

It is advisable to make the prints of cylindrical hor- 
izontal cores about equal in length to the diameter of the 
core. This may seem excessive and in some cases it 
may be, but it had better be too long than too short. 
When it becomes necessary to make them shorter than 
this on account of the size of the flask to be used, or of 
the core oven, and the casting is quite heavy, it is good 
practice to imbed a plate of iron in the mold for the core 
to rest on, thus the weight of the core will be distributed 
over a larger area of sand than the core -print alone would 
afford. 

A great many castings are lost because the lower 
print of vertical cores are made nearly parallel or with the 
ordinary pattern draft. The probable cause of this is 
that the core does not go down to the bottom of the mold 
since the sand is cut down by the core on setting. So 
when the cope is closed, being too long, it breaks the 
mold around the print of the core, allowing metal to flow 
into the vent and thereby causing the casting to **blow." 
This may be overcome to a large degree by tapering the 
lower print as is usually done in the case of the upper 



CORKS 43 

one. If this is attended to there can be no trouble in 
setting the core. Indeed, in the case of small cores, the 
molder can set them enough faster to pay for the extra 
work of pasting such cores together. As this is the main 
objection to this shape of print, viz., the necessity of 
making the cores in halves, it will be more than overbal- 
anced by the advantage of the greater facility and rapid- 
ity with which the cores can be set, to say nothing about 
the larger output of SOUnd castings. 

The subject of taper core -prints for vertical cores is 
one of considerable importance, especially from the 
molder's standpoint. It is well to adopt some standard 
taper, so that if a core-print is lost, another may be made 
of the correct size whether the core box is in sight or not. 
Probably the best taper for the purpose is one of one- 
fourth inch to one inch in height. This is an easily 
remembered taper and will give entire satisfaction to the 
molder. This taper can be employed for all vertical 
prints large or small, (the smaller sizes being reduced in 
length) one inch is long enough for any size of cylin- 
drical vertical core. A good rule to follow for cores less 
than one inch in diameter is to make the length of the 
print equal to the diameter, while preserving the same 
taper. It might be objected that one inch is too short 
for large cores, say of 12 inches or more in diameter. 

But there is not much strain on the print, that is on 
the print in the sand of the mold which holds the core in 
place, — for it simply locates the core. Nearly all the 
strain, if, to be sure, there is any, comes on the end of 
the core. Therefore, any extra length given the print 
would be of no advantage, and one inch is as good as a 
greater length. One reason why there is but a slight 
strain on the sides of these prints is that the metal on 



44 



WOOD PATTERN MAKING 



being poured into the mold completely surrounds the 
core so that the pressure is practically equal in all direc- 
tions. This, however, is not the case with the horizon- 
tal cylindrical core. As has been already mentioned a 
taper of one -fourth inch on each side is the best. This 
is illustrated in Fig. 12, where it is reduced to a system. 
In this system, for cores that are less than one inch in 
diameter, the dimensions of the print are derived from 




^^ ^ Ut^ 




Fig. 12 

the diameter of the core; for instance, if it is required to 
provide for a core that is seven -eighths inch in diameter, 
the length of the prints will be seven -eighths inch, or 
the diameter of the core, the large diameter also, seven - 
eighths inch, the small diameter seven -sixteenths inch 
or one -half the large. Therefore, in using this system, 
all that we need to know is the diameter of the core, and 
this will give the other dimensions. Now if a print is 
lost, as often happens, another can be made without 
seeing the core box, if this system is carried out for all 
cores of this kind. 



9 



9 



9 

to 

o 




^ :;JW 



CHAPTER VII. 



holders' joints or partings. 



The jointing of patterns is fundamental, and must be 
considered from two points of view; that of the molder, 
and that of the wood -worker. The first is concerned 
more particularly with the removal of the pattern from 
the mold, or, as the molder expresses it, pulling the pat- 
tern. The second is constructional, and into it enters the 
combination and arrangement of the different pieces of 
wood composing the pattern. The joints that are 
arranged for the purpose of removing the pattern from 
the mold are usually called partings, or pattem-maRcrS* 
partings, and strictly speaking, are not joints. The joints 
made in the construction of the pattern are true joints, 
and should be made as nearly perfect as possible, since 
the strength and durability of the pattern depends largely 
on their efficiency as joints. 

The first mentioned of these joints, the molder's part- 
ings, will be considered in this chapter. Whether a 
pattern is made correctly or not, from the molder's 
standpoint, will depend largely on the understanding 
that the pattern-maker has of these partings, and of 
their position in the mold itself. In order to explain 
these points a few examples will be mentioned. It 
requires at least one of these molder's partings for every 
pattern, as the mold must consist of two bodies of sand, 



MOI.DKRS' JOINTS OR PARTINGS 



47 



SO that the pattern may be taken out. The simplest 
form of pattern is a square block like that represented by 
Fig. 13. The parting will be made on the line A B, 





Fig. 13. 



Fig. 13 (a) 



the part of the mold below that line being in the nowel ; 
in this case all the mold will be in the nowel, the cope 
forming the top surface only. The next in point of 
simplicity is known as a Simple parted pattern, and is 
represented by Fig. 1, on page 6. In a mold made off 
this pattern, one-half would be in the nowel, and one- 
half in the cope, as represented by Fig. 13 (a). The 
line A B is the parting line of the mold and also of the 




Fig. 14. 
pattern. In this form of pattern, it will be noticed, the 
molder's parting and the pattern-maker's parting exactly 
coincide. When a pattern is so made that the partings 
can be arranged in this way, the molding may be very 
easily and quickly done. The process of molding such 
a pattern is described in Chapter II. Fig. 14 may be 



48 



WOOD PATTERN MAKING 



considered typical of a large class of pattern work. It is 
a pattern for a small car wheel having a central web. 
The molder's parting will be made on line A B. No 
parting is required in the pattern except that the boss, or 
hub, C, is usually left loose, so it will lift with the cope. 
Fig. 15 represents a pattern of a double flange wheel, 
and is a good example of a class of patterns where the 
molder's and pattern-maker's joints dO not coincide. 



^ 



^ 






I \ 



JL 



> 



L...J 

r , 



^ 



Fig. 15. 
This would need what is called a three-part flasR, meaning 

that the mold is composed of three distinct bodies of sand, 

which, of course, involves the making of two molder's 
partings. One of these will come in the centre of each 
flange or lines A B and C D. The pattern will be 
parted at B F. The sand, or cores, that will form the 
part of the mold at G and H will be lifted with the cope 




-AK 



Fig. 16. 
down to the upper line of the web. The mold for a worm 
wheel is another good example of molding where the 
parting of the pattern does not coincide with that of the 
mold Fig 16 will make this quite clear. The pattern 



holders' joints or partings 



49 



will be parted along the line AB; the molder's partings, 
of which there must be two, will come on the lines C D 
and G H. All of the teeth will come in the middle part, 
or cheek, included in the space K. The two halves will, 
of course, be drawn from the mold in opposite directions, 
the inner curves of the rim, and the taper of the hub, 
affording plenty of draft. There is another form of 
molder's parting known as an "irregular parting," that 
must frequently be used on account of the shape of the 
pattern. The pattern represented by Fig. 17 is an 
example of this form of parting. In the molding of this 
pattern the molder's parting will be made along the 




Fig. 17. 
dotted line DD, so that the most of the mold will be in 
the nowel, which is very desirable, as it leaves less to be 
lifted by the cope. As indicated by the tapered prints 



50 



WOOD PATTERN MAKING 



shown at A and B in Fig. 50, a core will be used for 
forming a round hole through the casting. Another, 
but a more simple joint of this kind is shown by Fig. 18, 
which represents a cast-iron bracket. The parting of 




Fig. 18. 
the mold will be made along the dotted line AB. If a 
number of comparatively small brackets of this shape is 
wanted, the pattern can be parted through the central 
web, or a follow board can be made and fitted to a one- 
piece pattern. 




Fig. 19. 
A contrivance frequently used in molding, called 
sRcWCrin^ on loose pieces, saves considerable time and 



HOLDERS JOINTS OR PARTINGS 



51 



work in both pattern shop and foundry. An example of 
this is illustrated by Fig. 19, which represents a part of 
a cast-iron base for a wood -working machine. The 
whole casting is cored out; and, for convenience in 
molding, the pattern was boxed up to form a one-piece 
pattern, to be pulled from the mold in the direction indi- 
cated by the arrow. If the two bosses, A and B, were 
fastened on , they would tear up the sand . In order to pre - 
vent this they are sKcWCrcd On, that is, held in place tempor- 
arily with wire'skewers, as shown. As the mold is being 
rammed up, after sand enough has been rammed around 
the bosses to hold them in place, the skewers are pulled 






Fig. 20. Fig. 21. 

out. This, of course, allows the main pattern to be 
pulled out, thus leaving in the mold these loose pieces 
which can be pulled sidewise into the mold. Of course, 
this pattern could be parted through the center line, but 
that would entail a large amount of extra work in both 



52 WOOD PATTERN MAKING 

the foundry and the pattern shop. By the use of this 
method, therefore, the extra work of making another 
parting is saved. Another way sometimes adopted for 
forming projections on a casting is made clear by Figs. 
20 and 21. They represent a hollow, cylindrical cast- 
ing, with a flange on both ends, a projecting boss for a 
pipe on one side about midway of its height, and an 
opening through the top. The pattern will have to be 
parted on the line CC, and will require a three -part 
flask, with molder's parting along line BB. To form the 
projection on the side, one of two methods may be 
adopted: One, the use of a core print and core; the 




Fig. 2L 

other a core only, to be set in place at the time of ram- 
ming up the mold. If the second method is used, all 
that the pattern-maker needs to do is to make a core box 
with a pattern projection located in it. 

This core box is represented by Fig. 22. If the first 
method is adopted, a core print will have to be put on 



MOLDKRS' JOINTS OR PARTINGS 53 

the side of the pattern, so as to extend from the top 
parting down to a point just below the projection. If a 
hole is to be cored through the projection, this would be 
the best way of doing the job. 

The examples given above of molder's joints do not 
introduce nearly all the ways and means employed by the 
molder for making molds. But they do give a good gen- 
eral idea of the most common ways, and will afford such 
suggestions to the beginner in pattern -making as to 
enable him to make patterns so that they can be 
"pulled" without injury to the mold. This should be 
the first consideration of the pattern-maker, as on it 
depends in la large degree the accuracy of the casting. 
If the mold is injured in any way by the pulling of the 
pattern, so that the molder has to mend it, the casting 
is rarely correct in shape. In the next chapter, the mat- 
ter of constructional joints will be taken up, that is, the 
building of wood patterns from the view point of the 
wood -worker. 




o 



a 



to 

O 



CHAPTER VIII. 



CONSTRUCTIONAL JOINTS 



In a consideration of this part of the general subject 
of pattern -making, two things must be given prominence, 
viz. : the strength and durability of the pattern, and its 
permanence of form. This latter is very likely to be 
interfered with by the absorption of moisture from the 
damp sand, thereby causing the wood to swell, and per- 
haps to warp. The amount of moisture thus absorbed 
depends upon the time the pattern has to remain in the 
mold, and upon the condition of its protective coating of 
varnish. To overcome any change likely to take place 
from this cause, several methods of arranging the various 
pieces of which the pattern is built up, are used. The par- 
ticular method to be employed in a given case depends 
on the size and shape of the pattern, and also depends, 
to a degree, on whether a large number of castings is 
wanted or only one. In order to secure the requisite 
permanence of form, it is better, other things being equal, 
to build a pattern of several pieces rather than to cut it 
out of one piece. For then the warping in the whole 
pattern is reduced to a minimum. In small patterns, 
however, this warping may be disregarded; therefore, a 
small pattern may be cut from a single piece of wood. 
This matter of constructional joints may be most easily 
comprehended by studying examples of forms likely to 
be required. 



56 



WOOD PATTERN MAKING 



When thin disks are wanted it is best to build them 
up of three layers with the ^rain of the pieces running 
tangentially to a small circle in the center, as illustrated 
by Figs. 23 and 24. The grain of the wood must run 




Fig. 23. Fig. 24. 

lengthwise and parallel to the longest side of each sector. 
After the pieces have been fitted together, a groove is 
cut in the edge of each, in which tongues of wood are 
glued and driven as illustrated by Fig. 24. When one 
disk has been glued up and the glue has dried, the sec- 
tors for the other disks may be glued directly to it with 
the joints running across the others, the angle depending 
on the number of sectors used to form the circle. This 
makes a very rigid construction and one which will no 
warp. 

If in building a pattern a thin, wide board is required 
and the other parts of the pattern are of such shape that 
they do not afford to it sufl&cient support to keep it from 
warping, a good way is to rip the board up into strios of 



CONSTRUCTIONAL JOINTS 



57 



from two to four inches wide (according to the width of 
the required board) and then glue the strips together 
with each alternate strip reversed, as shown in Fig. 25. 
In this way the warping will be reduced to the minimum 
because the alternate pieces are inclined to warp in oppo- 
site directions. 

A good way to support patterns of this general shape 
during the process of molding is illustrated by the lower 
part of Fig. 25. The additional pieces B and C are called 
counter ribs. The recesses made by them in the sand will 
be filled by the molder, or, as he expresses it, they are 
"stopped off in the mold." The shape of these counter 
ribs, which is more clearly shown at D, indicate to the 




Fig. 25. 

molder that they are to be stopped off in the mold. When - 
ever possible these should be put on the pattern so they 
will come in the nowel of the mold; these are also called 
"stop-off" pieces. Another way of building patterns 
that are round and flat and are supported by segments 
running around them, is to make the flat part of several 
strips rather than of a wide board. This is illustrated by 
i ) r 1 ese strips should not be glued together, hv^ 



58 



WOOD PATTERN MAKING 



held in position by the segments that are built on to 
them. If the pattern is more than 12 inches in diame- 
ter on the inside, it is advisable to insert at least one 
dowel in each of the joints between these strips to keep 




Fig. 26. 
them from springing sidewise. This need be done only 
for three or four of the joints near the center. A "slip" 
tongue joint may also be used instead of dowels. An- 
other way to overcome the effect of shrinking and swell- 
ing in large patterns is the use of what is termed Open 

joints. 




Fig. 27 



-Fig. 28 



If it is required to build a large pattern that is flat 
and comparatively thin, either circular or square, it 



CONSTRUCTlONAIv JOINTS 59 

would be built as shown by Fig. 27; that is, the sides 
would not be built up by gluing narrow boards together, 
but they would be laid side by side with open joints 
between, of from one -sixteenth inch to one -eighth inch 
in width, and a slip tongue inserted. If the boards 
expand with moisture the width of the pattern as a whole 
does not increase ; the only effect is to partly close these 
open spaces. If the boards shrink the only effect is that 
the spaces increase in width. As broad -plated work is 
usually stiffened with ribs and flanges, the fact that the 
joints are open will not lessen the rigidity of the pattern. 
If a case should occur where there could not be support 
enough in the pattern itself, then the boards could be 
held in place as shown in Fig. 27, by a method which 
is practically paneling. A frame is made as for a panel 
door, and the ends of the boards fitted to a groove. 

This method may be used in connection with what 
is known as boxing up a pattern. This is illustrated in 
Fig. 28. Open joints are represented at a, a, a, Fig. 27. 
This method, bOXing Up, is frequently used for large pat- 
terns which if made solid would be unduly heavy and 
would be especially liable to become affected by mois- 
ture and dryness. The rebated joint should always be 
used at the corners in boxing up a pattern that is of a 
square or rectangular cross section. This is illustrated 
by Fig. 28. If the pattern was to be pulled from the 
mold in the direction indicated by the arrow, and was 
built as at (a) Fig. 28, then any change due to shrinking 
or swelling of the relative position of pieces b and c 
would leave an uneven surface on the vertical side which 
on being pulled from the mold would be likely to tear up 
the sand and thereby cause the molder some trouble 
If the joints are arranged as at (A) Fig. 28 this cannot 



60 



WOOD PATTERN MAKING 



occur. This form of ioint has another advantage, for if 
the joint were simply a butt joint, the ramming of the 
sand of the cope down on the face (E) would be likely to 
drive the top board down below the edges of the sides, 
but in this case, the piece K, being rebated into A and C, 
cannot be driven down. 

Fig. 29 represents an example of another type of 
hollow work, which, however, is not called boxing up, 
but lagging or lag^in^ up. This method may be defined 
as the building of patterns with longitudinal strips that 
run parallel with the axis of the proposed cylinder. It 
is used for turned work. The figure represents a sec- 
tion of the pattern of a pipe or column of any diameter 
ver four or five inches. A A is the joint of both pat- 




FiG. 29 

tern and mold. B B are cross bars of polygonal shape 
on which the strips or lags are laid and fastened with 
glue and screws. The lags are also glued to each other 
except on the line A A. 

Fig. 30 illustrates another way of building by lag- 
ging. In this way much narrower strips are used, there- 
by reducing the work of turning and also requiring less 
lumber-. The parts for the core prints are built up first, 
and then the lags for the rest of the pattern are fitted an 



CONSTRUCTIONAI. JOINTS 



61 



glued and screwed to these, as is indicated by the figure. 
Should the body of the cylinder be long, two or more 
semicircular discs must be used to insure rigidity. Fig. 
31 shows how this method of building up may be used 
for large cylindrical core boxes. If the work is done 
accurately, the work of finishing the inside of the box is 
reduced to a minimum. 




Fig. 30. 



Fig. 31. 



When annular patterns of six inches or more in 
diameter are wanted they are made by what is known as 
building up Witll segments. This is illustrated by Fig. 32, 
and when properly done makes a very strong construc- 
tion. The several pieces should be cut from the board 
in such a way that the grain of the wood follows the 
circle as near as may be. Therefore, in laying out the 
segments the chords of the curves should be parallel to 
the grain of the wood. In building patterns of this type, 
a number of short segments are sawn out and glued in 



62 



WOOD PATTERN MAKING 



courses, one over the other with the end joints alternat- 
ing or breaking joint, when the glue is dry the correct 
outline is imparted by turning or otherwise. By this 
construction shrinkage in the segments is reduced to 
practically nothing. 




Fig. 32. 

Examples of constructional joints of still another 
type of patterns, sometimes termed plate work, is repre- 
sented by Figs. 33 and 34. Fig. 33 shows a frame 
cut from solid wood, 18 inches wide and 2 feet 6 inches 
long, by 1 inch thick. It is clear that strength and per- 
manence of form is entirely lacking in bars (a a). 
Contrast the construction in Fig. 34. In this there can- 
not be any material alteration in width or length, in gen- 
eral or local dimensions, and there is the maximum of 
strength. The frame is made of five narrow strips. 
Alternative methods of making half lap points are shown. 
At the corners plain halving is shown. At D the dove- 
tailed form of halving is illustrated. The plain halving 
if properly made, glued and screwed, is very strong 



CONSTRUCTIONAL JOINTS 



63 



and permanent. For standard patterns, however, it is 
advisable to employ the dove-tail form. 

Another example of this same type, but of 
a very distinct form, is shown by Fig. 47. The 
finished casting is shown by Fig 46. It will be 
noticed that the joints are of the half -lap form. This 
figure (Fig. 47) shows the plate part of the pattern only, 




Fig. 33. Fig. 34. 

made up of three pieces. The pieces are so arranged 
that wherever there is a curve there is wood with the 
grain running practically tangent to it; consequently, if 
the joints are properly made and glued, it can be worked 
into shape without being broken out. Moreover, there 
is wood enough at all the angles so that the fillets may 
be worked in the solid wood instead of separate pieces 
being glued in for the fillets. For standard plate work 
it is always best to do this, even if it does take wider 
material. The added durability will more than pay for 



64 



WOOD PATTKRN MAKING 



the extra lumber, and then it also saves the time of mak- 
ing and gluing in the separate pieces. 

Round corners maybe formed, as shown by Fig. 35. 




Fig. 35. 

In this case the two pieces, A and B are joined in the 
usual way with a butt joint as at C; the piece D is glued 
into the angle and allowed to stand long enough to dry ; 
then the corner is worked to the required form outside 
and inside. In work of this kind it is best to work the inside 
first, because the piece can usually be held better if the 
outside corner is square, than if it is rounded. The 
block, after being fitted to the angle, may be sawed or 
planed to form, as indicated by lineB. This can be done 
more easily before, than after it is glued in place. 

As pattern -making is one of the most comprehensive 
of trades, and the demands of the engineering profession 
for complicated castings are limitless, it is impossible to 
anticipate the next forma pattern-maker will be called on 
to make. This being the case, only general methods can 
be considered in a volume of this size, treating on the 
subject. The joints and methods of construction that 
have thus far been considered are those most frequently 
employed in pattern -making. Special examples of types 
of pattern -making will next be taken up, for which one 
or more methods of construction will be given in detail. 




Clement Universal Bench Saw 




Williamsport Scroll Saiv 



CHAPTER IX. 



SPECIAL TYPES OF PATTERNS. 



Before taking up the subject of making special types 
of patterns, certain matters that apply, not only to special 
types, but to all patterns, must be considered. 

One of these is the preparation of the lumber. 

This consists in the first place of cutting roughly to 
size, the several pieces required for making the proposed 
pattern. They are then allowed to stand for as long a 
time as the job will allow, so that they may warp into 
and assume a nearly permanent form. If this is done, 
when they are cut to the final shape, they will not again 
warp and change the original form of the pattern. This 
additional seasoning is necessary, because lumber will 
change more or less in shape, when much of it is cut 
away, exposing a surface that has heretofore been on the 
inside of the plank or board. The foregoing constitutes 
the first step and may be termed Cutting thc Stuff POUghly tO 
size. The next step is planing up one or two sides to a 
true plane, and marking them as Working faCCS. Usually 
these planes should be made at right angles to each 
other. This is quite important, as, generally speaking, 
the accuracy of the work will depend to a degree upon 
the accuracy of these two faces. All lumber to be used 
in making patterns should be planed by hand before 
being put into the pattern, especially if a flat surface is 



SPECIAL TYPKS OF PATTERNS 



67 



desired. The ordinary rotary knife planer will not plane 
stuff fiat, therefore the hand plane must be used. If 
there is a Daniels planer in the shop it may be used to 
plane one side of the board ; the other may be passed 
through the ordinary planer. But even if this is done, 
the lumber should be planed by hand to insure a good 
finish, as the rotary knife will leave the surface more or 
less corrugated. 

The simplest patterns are those which are made in 
one piece, and which require no coring, although the 




F all over 




Fig. 36. 



Fig 37. 



castings themselves may be hollow. In commencing a 
pattern, one must first decide how it is to be removed 
from the sand, and where the parting line, if one is 
needed, should be. 

A simple one-piece pattern, around which to form a 



68 WOOD PATTERN MAKING 

mold with a dry sand core, is exemplified by ihe stufiing 
box gland shown in Fig. 36. This figure shows the 
finished casting, which is to be finished all over. 

This is a type of a very large class of patterns 
which must be cast on end. It is what is generally 
known as a stufiing box gland. The finished casting is 
represented by Fig. 36, the finished pattern by Fig. 37, 
and the requisite core box by Fig. 38. Fig. 36 repre- 
sents also the drawing that would be sent to the shops. 
The gland is made from this drawing. 

Considering this pattern from the molder's stand- 
point, it is clear that if it is molded endwise, with the 
flange up, and if the molder's parting is made along the 
top of the flange, it can be readily pulled. The draft in 
this case should be one eighth inch for 12 inches. Each 
core print should be one inch long. When the amount of 
draft and finish is decided on, it is a good plan to make a 
full size sketch of the pattern as it will appear when 
ready for the molder, and with all required dimensions 
plainly shown on it. This should be done before one 
begins to make the pattern. Indeed, one may well fol- 
low this in the case of every pattern, for thereby many 
mistakes and much loss of time will be avoided. Accord- 
ing to the drawing Fig. 36, this gland is to be finished 
all over, so that in making the pattern there must be 
allowance for both finish or machining, and draft. As 
none of the dimensions are over six inches in any one 
direction, shrinkage may be disregarded. As this pat- 
tern is to be pulled from the mold endwise, the draft on 
the outside will have to be like that shown by Fig. 3, 
on page 14. One way to make a pattern for this casting 
is shown in Fig. 36 (a). If it is made in this way, it 
may be molded and leave its own core, but the hole can- 



SPECIAL TYPES OF PATTERNS 



69 



not be made parallel. It is usual to allow double the 
amount of draft on the inside for all small cores similar 
to this one. This would make considerable more work 
for the machine shop if the hole had to be finished. For 
this reason, if a large number was wanted, the pattern 
would be made as described in the following pages : 

To make this pattern it will be necessary to build 







Fig. 36 (a) 

Up a block of wood that is at least 3Mx3%x7 inches 
long. The best way to do this is to use two pieces 1/4 
inches thick, and one piece three-fourths inch thick, glu- 
ing them all together, with the thinner one in the middle. 
In gluing up work of this kind, it is always best to have 
the thicker pieces on the outside ; for if the piece on the 
outside is too thin, it will, during successive moldings, 
be likely to become loosened on account of the action of 
the damp snnd on the glue. As soon as the glue is quite 
dr}^ the corners may be cut off with an axe or a chisel 
and mallet. The piece is now ready to be mounted in 
the lathe, and should be turned to a cylinder of three 
and five -eighths inches in diameter, which is the out- 
side dimensions of the flange. Now, laying a rule 
along the tool rest up against the cylinder, point off the 
measurements as indicated by the drawing, preferably 



70 WOOD PATTERN MAKING 

commencing at the right hand end, that is, next to the 
back or dead center of the lathe. By commencing at 
that point any surplus material will be left at the other 
end, so that it will not be necessary to get so close to the 
chuck or driving center with the tools. First, then, 
make a mark about one -sixteenth inch from the right 
hand end for the end of the print. From this point 
measure one inch for the- length of the print; from this 
measure three and three -fourth inches for distance from 
the end of the pattern to the under side of the flange; 
from this point measure three -eighths inch for the thick- 
ness of the flange ; from this mark measure one inch for 
the length of the print on this end. Check up by measur- 
ing total length between the outside marks, which should 
be six and one-eighth inches. Now hold the point of a 
pencil at each of these marks, allowing the side of the 
pencil to lay on the tool rest; give the belt of the lathe a 
pull which will turn the cylinder, making a mark all the 
way around it. Now cut the cylinder to the required 
size below the flange, remembering that the core prints 
will have to be tapered, because this will be a vertical 
core. Now, if the successive steps have been done cor- 
rectly, the pattern will be like Fig. 37. The top print 
should be loose for the convenience of the molder. All the 
lathe work on this pattern should be done with scraping 
tools, except that the gouge should be used for roughing 
it to the approximate diameter. 

The next thing will be the making of the core box 
in which to make, or form, or mold the dry sand core. 
This box is shown by Fig. 38. This being a symmetri- 
cal core, one half box will be enough. To make this 
we proceed as follows : Take a piece of straight -grained 
pine, of such a width that after the semicircular groove 



SPECIAL TYPES OF PATTERNS 



71 



forming the body of the box is cut out, there will be left 
about three -fourths inch on each side. In this case, the 
box being two and one -quarter inches in diameter, 
and one and one-half inches for the two sides, the width 
of the piece will be three and three -fourths inches. The 




Fig. 38. Fig. 39. 

depth of the groove will, of course, be one and one- 
eighth inches, and there should be at least seven -eighths 
inch thickness of wood below this, which will make the 
required block 2x3^ inches and five inches long. 
The block should be planed on all sides ; one of the wide 
sides (for the top of the box,) and its adjacent narrow 
sides are to be straight and exactly at right angles to 
each other. To lay out the lines for this, fasten the 
block in the vise with one end down even with the top of 
bench, or vise. Now set the dividers to the radius of 
the required curve, one and one-eighth inches, and put 
one leg of the dividers in between the block and the vise 
jaw, on the side intended for the top of the box, approxi- 
mately in the center of the side; then describe a semi- 
circ e on the end of the block, as shown at Fig. 



72 



WOOD PATTERN MAKING 



39. Now with the gauge set to the distance c to a, 
make a mark along the top or face side for the whole 
length from the point a, then extend the gauge 
to point b, making another line the whole length 
of the block. On the other end make another 
semicircle. This completes the laying out of the core 
box The wood must now be taken out just to these 
lines. This may be done in two ways, the better of which 
is by the use of the core box plane. This is a plane whose 
face instead of being just one surface, is composed of 
two surfaces set at right angles to each other, as shown 
by Fig. 40. The cutting iron is narrow, and ground to 




Fig. 40. 
an acute angle, so as to conform to the shape of the plane 
at the apex of the angle forming the two sides of the face 
of the plane. The principle of its construction and use 
is, that the greatest inscribed angle in a semicircle is a 
right angle. The whole of the wood on the inside of 
semicircle cannot be cut out with this plane, so first 
use a gouge to cut it out to within one -eighth inch of 
the mark ; then cut it exactly to line along both gauge 
marks; then, holding the plane in such a way that 
the fingers of the left hand will form a guide to keep the 
plane to the line, cut a shaving along the line on the side 



SPECIAL TYPES OF PATTERNS 



73 



farthest from the operator. This is illustrated by Fig. 41 , 
in which the upper curved line represents the work as 
done by the gouge, and the semicircle immediately below 
it is the circle to which the work is to be cut. There is 
now a guide for both sides of the plane, so that by exer- 
cising a little care the plane may be passed along through - 




Fig. 41. 

out the length of the block, cutting a shaving at each 
stroke. This may be continued until about one -third of 
the whole is worked out. Now the block may be turned 
end for end, and the other side treated in the same way 
down to about midway of the distance; then turn the 
block again and finish the other side. This will make a 
very neat and accurate job if the plane is in proper con- 
dition. Another way by which the plane may be started 
is to nail a thin strip of wood along the gauge line as 
represented at (a) Fig. 41. This is used as a guide for 
the plane. After the groove has been cut down a short 
distance (about one -sixteenth inch), this extra piece 
must be removed to the other side and again used as a 
guide. This guide piece must be taken away before work- 



74 



WOOD PATTERN MAKING 



ing the groove down very much, for if allowed to remain 
it would change the size of the semicircle made by the 
plane. The cutting iron of the plane should be so 
sharpened and set as to cut on one side only, preferably 
on side A, Fig. 40. If it is allowed to cut on the other 
side, and used as indicated by Fig. 41, it will cut the 
groove too large, making the core box larger in diameter 
than wanted. Another way to cut out this part of the 
core box is to use a gouge to remove almost all the 
material, using a round plane to finish with. Doing the 
job in this way will involve the use of a straight edge to 
test the straightness of the work from end to end. For 
this purpose, a straight edge with a thin cross section is 
necessary. A try -square if long enough, is a very good 
tool for this purpose. 




Fig. 41(a). 
It will be a great advantage to set the cutting iron so 
it will cut the wood on one side of the plane only. In 
order to do this it is best to cut away a small amount of 
wood on one side of the plane, as indicated at A Fig. 40. 
This plane is almost indispensable for making core boxes 
of the shape represented by Fig. 41 (a) , for what may be 



SPECIAL TYPES OF PATTERNS 75 

called conical cores. As the curve changes continually 
throughout the entire length, it is almost impossible to 
make a cavity that is uniform, if one uses the gouge and 
round plane. A straight edge and templet must be used 
frequently to test the work. But the core box plane 
overcomes all these difficulties, and if only the two sides 
of the cavity are correctly located, and then worked to 
the lines with the gouge, the plane will do the rest of 
the work. There are machines on the market which do 
this kind of work very accurately and rapidly. One of 
them is illustrated on page 45. This is the Crane Core 
Box Machine. 

Whichever method is used in making this part of 
the core box, it needs to be smoothed on the inside with 
sandpaper. If the box is small, this is best done with 
sandpaper placed around a cylinder of wood, the cylinder 
being about one-fourth inch smaller in diameter than the 
box. If the box is large, a piece of wood about four or five 
inches wide and an inch thick, with one side planed 
approximately to the curve of the inside of the box, will 
be better. 

To form the ends of the box marked A A in Fig. 38, 
the following is the best way: Make two pieces of wood 
four inches long and two inches wide, and exactly 
one inch thick. Plane them so that two of the narrowest 
faces will make a good joint at right angles to the wider 
sides. Now face up a chuck about six inches in diam- 
eter, and while it is revolving in the lathe, make a fine 
pencil mark or dot in the center. Place one of the pieces 
flat on the chuck, so that one of the face edges will pass 
through this dot mark; nail it to the chuck in this posi- 
tion, and then place the other piece alongside, and nail 
it also. If this work is correctly done, the chuck, with 



76 



WOOD PATTERN MAKING 



pieces nailed on, will look son:ething like Fig. 42. This 
is now to be put on the lathe, and a hole of the shape of 
the core print on the pattern turned into it. If the 
blocks were properly placed, each will have a semicircular 
hole in it, representing one -half the frustrum of' a cone, 
whose dimensions correspond exactly with those of the 
core print on the pattern. These are now to be taken 
from the chuck and nailed and glued, one on each end of 
the body of the box previously made. This must be cut 
to the exact length required, which in this case will be 
four and one -fourth inches. It is necessary that a core 
box for a Vertical core should be about one -eighth inch 




Fig. 42. 

longer than the pattern, so that the cope of the mold will 
be sure to fit tightly around the core ; then no metal can 
flow up alongside of it and over the end of the core, 
thus covering up the vent and causing the casting to 
blow. For the above reason all Vertical cylindrical cores 
should be one -eighth inch longer than the total length 
of the pattern and prints. To complete the box it is only 
necessary to nail pieces (B B. Fig. 38) one on each end, 
and then give a taper at the point C. To make the core, 



SPKCIAI. TYPKS OF PATTERNS 



77 



two halves are made in this box; after drying, they are 
pasted together, making a complete core. 

The next example is very similar to the former one, 
but, having a flange at both ends, it will have to be 
molded horizontally, and will therefore require a horizontal 
core The completed casting is represented by Fig. 43, 
and a pattern for producing it by Fig. 44. On account 





Figs. 43. 




Fig. 44. 



Fig. 45. 



of the shape of this casting it will be best to make the 
pattern a parted pattern. This will save the molder some 
time and work, as it will give a form that is easily 
removed from the sand. In making this pattern, the 
first thing to do will be to get two pieces of wood of such 
dimensions that when they are put together the pattern 
can be turned out of them. As will be noticed by the 



78 WOOD PATTERN MAKING 

drawing, there is no finish required except on the face 
of the flanges. Allowing for finish, the length of the 
pattern without the core prints will be six and one- 
fourth inches. The core is to be one and one-half inches 
in diameter, so the prints will be one and one -half inches 
long; then two inches more must be added for fastening 
together at the ends, making a total of eleven and one- 
fourth inches for rough size. Two pieces then are 
needed, eleven and one -fourth inches long, four inches 
wide and two inches thick. The next step will be to 
plane one of the larger sides of each piece to a true sur- 
face, to form a joint between them. 

The next thing is to locate the holes for the pattern 
pins that will be necessary to locate the two halves in 
relation to each other after being separated. The most 
practical way to do this is as follows : On the plane sur- 
face of one of the pieces locate these holes with a pencil 
mark; this mark to be, say four and five inches from a 
center line approximately on the center of the width. If 
the pins are thus located, the molder will not err in 
putting the two halves together, for if he happens to do 
it incorrectly, he will at once recognize his mistake. 

Having marked the points where it is desired to put 
the pins, take two small brads and lay them on the 
block with the heads at these points; now carefully lay 
the other piece on these brads, and having brought it into 
exactly the desired position, strike the top piece a light 
blow with the hammer or mallet. This will cause the 
heads of the brads to make corresponding impressions on 
both blocks. At these impressions, bore holes one-half 
inch deep. The diameter of the hole is of small moment; 
for patterns of this size, one -fourth inch is about right ; 
the larger the work, the larger the pins should be. 



SPKCIAIv TYPES OF PATTERNS 79 

The next thing will be to make the pins, for which 
a piece about ten inches long will be found the best. 
Select a piece that is straight in the grain, and rip to 
such a size that one side of the square stick equals the 
diameter of the hole, plus one-eighth of an inch. With 
the jackplane plane this into an octagonal form. Then, 
grasping one end in the left hand and laying the other 
end on the bench, with the block -plane plane off the 
the corners, making it as nearly round as possible for 
about three inches of its length. This round part should 
be made to fit the hole exactly, that is, at the extreme 
end. With knife and sandpaper, or file, round this end 
to an approximately parabolic form. Now set it into the 
hole in the piece into which the pins are not to be fas- 
tened, far enough so that it exactly fits the hole. Make a 
pencil mark part way around it, right at the surface of 
the block. Now measure the depth of the hole into 
which the pin is to be fastened, and mark this distance 
along the pin from the mark previously made. This is 
the point at which to saw the pin off. Now, if this pin be 
driven down into the hole clear to the bottom, the first mark 
will come even with the parting and will exactly fit. By 
means of these pins, the two parts, after being separated, 
may be brought together again in exactly the same 
relative position, and will be held firmly so that they will 
not slide or shift sidewise during the process of molding. 
They should be loose enough so that the pattern will fall 
apart of its own weight, but still not loose enough so that 
there is any perceptible movement sidewise. When both 
pins are in place, the blocks are ready to be fastened 
together. There are three ways in which this may be 
done. If there is time to wait for glue to dry, the best 
way is to put glue on the ends of each piece for a dis- 



80 WOOD PATTERN MAKING 

tance of about one-half inch, and clamp them together 
with a handscrew or other clamp. If it is desired not to 
wait for the glue, then a screw may be put through the 
ends, fastening them together in that way. It is advis- 
able, for convenience in turning, to use a short screw, 
boring a hole large enough to receive the head of the 
screw. For a piece of this size a one and one -fourth 
inch screw may be used. If care is taken to have one- 
half the length of the screw in each piece, it can be turned 
to the required size of the print, out to the extreme end. 
The third method is to clamp them together with "dogs, ' ' 
which are small square staples made for the purpose. 
When the pieces are thus fastened together, they are 
ready to be placed in the lathe and the turning proceeded 
with. This may be done practically in the same way as 
in the previous example. One must allow for draft, and 
also for finish on the faces of the flanges, making these 
faces, and the ends of the prints convex as shown in 
Fig. 44. 

The next thing will be the core box. As this pattern 
requires what is known as a plain, cylindrical, horizontal 
core, and is therefore symmetrical, only a half-box is 
needed. But if it is desired to reduce the cost in the 
foundry, a core box like the one represented by Fig. 10, 
page 39, in the chapter on cores, would be used, the 
core being made complete at one operation. The half- 
box would be made as directed for the straight part of the 
core box in the last example, with end pieces, as repre- 
sented by Fig. 45 If a whole box is made, then 
the block would need to be twice as long, and worked 
out as in Figs. 38 and 39. After this is worked out, 
it should be cut in two pieces and pinned together in 
the same way as was done with the two pieces for the 



SPECIAL TYPKS OF PATTERNS 81 

pattern. One way that is quite practical is the fol- 
lowing: After cutting the pieces the correct length, 
place them together in their proper relation to each other; 
fasten them in the vise in a vertical position, with one end 
above the bench top, and bore a hole of the size required 
for the pin clear through the first piece and about half 
an inch into the other. Now by putting the pin through 
the hole, it will be filled and make an accurate and 
workmanlike job. If brass pins are used, this could not 
be done, because the pin would not fill the hole; and as 
the pin and its tube are of a different size, the hole could 
not be bored with the same bit. The inside length of 
this core box should be about one -eighth of an inch 
shorter than the total length of the pattern and prints, so 
that the core may be more easily set into the mold. 




Oliver^ ^ Bandsaw 



CHAPTER X. 



PI.ATK WORK AND IRREGULAR PARTING 



The next example to be taken up is typical of a quite 
large class of pattern - work, generally known as plate work. 
It is usually comparatively thin in cross -section in at least 
one direction. This class of work includes shafting, 
hangers of different patterns, some kinds of small pump 
standards, and any kind of work that is composed of two 
webs running into or crossing each other. This last is 
illustrated by Fig. 46. The example to be used to 
demonstrate the methods usually followed in building 
patterns of this type is represented by Figs. 46 and 47. 
In order to make the best pattern for durability and per- 
manence of form, the foundation should be built of three 
pieces, as shown in Fig. 47, which is almost self-explan- 
atory. Of course, this part of the pattern could be built 
of one piece of board, but it would be very weak through 
the portion marked A. By building it as represented, 
two things are gained; it is uniformly strong throughout, 
and smaller pieces of wood may be used. As in the case 
of all other patterns, so in this, it should be first deter- 
mined how the pattern is to be withdrawn from the mold. It 
will soon be seen that the best way will be to have the face 
marked B (Fig. 46) down in the nowel ; thus there will be 
left an almost flat surface for the molder's parting, which 
will then occur along line C D. It will, of course, be neces- 



84 



WOOD PATTERN MAKING 



sary to make part E loose, so it will lift with the cope 
sand. This is a type of what is known as lOOSC piCCCS 
molded in the cope and drawn therefrom after it is lifted 
off from the nowel, or lower part of the mold. The 




Fig. 46. 



method now to be described of laying out and building 
this pattern, may be used in building any pattern of this 



PLATE WORK AND IRREGULAR PARTING 85 

general type ; modifications of it may be introduced when 
needed. 

The first step to be taken in making this pattern is 
the making of two pieces of board about fifteen inches long, 
by two and one -half inches wide, and five -eighths inch 
thick, and one piece about nine inches long, four inches 
wide, and five -eighths inch thick. These must be 
planed on one side to a true plane, with the edges 
straight and at right angles to the side ; a faCC mark should 
be put on each piece. Now the two long pieces should 
be cut to shape, so as to make a good joint at F, care 
being taken that the two lower corners are far enough 
apart to include all of the pattern at that point. Tack 
these to the bench or laying-out table in their proper 
position with relation to each other; then locate points 
G H, and lay the third piece on the others with its edge 
at these points, and make knife marks across the two 
pieces. Now, without moving the third piece, make 
marks on it with the point of the knife at the points K, 
L, M, and N; then finish the laying -out, and cut out 
gains halfway through the two long pieces. Then cut 
out the ends of the short piece to the same thickness, 
but on the opposite side ; fit them together and glue them 
and put them in clamps till dry. While this is drying, a 
piece of board about fifteen inches long, six inches wide, 
and one-half inch thick, can be gotten out. Out of this 
can be sawn pieces for making the curved pieces that are 
built on to form the raised portions that are to be glued 
on to the main piece. These should be cut from the 
board so that the grain of the wood will run parallel with 
a chord of the curve, making the segment not to exceed 
one -quarter of the circumference of the circle. If they 
are made longer than this, there will be too much end 



86 



WOOD PATTERN MAKING 



grain. The straight pieces may also be gotten out at this 
time, so they will be ready when wanted. When the 
glue is dry on the three pieces that together form an 
A -shaped piece, it is to be planed on both sides to true 
planes until it is one-half inch thick. It is now ready to 
have the lines laid out on it as shown by Fig. 47. In 




Fig. 47. 



laying out these dimensions, the shrink rule should be 
used, as that will allow for the shrinkage of the metal in 
the casting. After these are all laid out, it may be sawn 



PIvATE WORK AND IRRKGUI,AR PARTING 87 

out on the band and jig saws. In doing this sawing, it 
is best to cut just outside the line, so that in filing and 
finishing the edges, the marks may serve as a guide. It 
is now ready to have the pieces set on to form the pro- 
jecting webs, which may be cut from the one -half inch 
piece already mentioned. It will be best to commence at 
the top of the pattern. 

The first will be a solid piece extending all over the 
upper end down to and including the semi -circle that 
joins the long outside webs. After this the other cir- 
cular parts may be cut out and put on. Now the pieces to 
form the feet may be made and glued in place ; then the 
straight pieces should be nicely fitted to these and glued 
in place. Now a piece of wood may be gotten out to form 
the fillet around the bearing where it joins the main part 
of the pattern. This should be about three -eighths inch 
thick, and should be large enough to extend three - 
eighths inch all round outside the bearing. For con- 
venience in cutting out the fillet, it is best to let the 
grain of the wood in this piece run parallel with the out- 
side line of the pattern at this point. A piece is also 
needed to go on the other side to form a fillet on which 
to pin the loose piece. (K Fig. 46.) Now a piece to form 
the bearing itself may be made. As this is required to 
be more than a half circle, it will be best to make it with 
the planes. According to the dimensions given, it will 
need to be of the following finished measurements : about 
four inches long, two and one -fourth inches wide, and 
one and three -eighths inches thick. It should be planed 
square to these dimensions, and a semi -circle described 
on each end, and then planed and sandpapered down to 
it. A piece can now be cut from this just two inches 
long, and fastened on top of the three -eighth inch fillet 



88 WOOD PATTERN MAKING 

piece. Both ends of this piece must be square, so it will 
set in a vertical position on one end, and so the core print 
to be made later will fit well. Apiece of this is required 
for the other or cope side, one inch long. This, how- 
ever, will not be fastened in place permanently, but will 
be pinned on so that it will lift with the cope 
sand when the cope is lifted off. The best 
way to do this is to place it in a correct position 
and drive two small brads through it, taking care not to 
put them where the pin holes are to be bored. Now, 
with brace and bit, bore two holes clear through it and 
into the other part of pattern to a depth of about one- 
half inch. A one-fourth inch auger bit is a good size to 
use for this purpose. 

Now make* pins as directed for use in the parted 
pattern on page 78. In this case they can be put through 




I. 



Si ■ 

Fig. 48. 

and fill the holes, as they will have to be on the loose 
piece. 

The next thing will be to make the core prints. 
These will extend the whole length of the bearing, and 
of course the length of the prints besides, and as this is 
a vertical core, will project one inch beyond the pattern 
on each side. To make these prints for this particular 
job, take a piece of wood about seven inches long and 
one and one -half inches square, place it in the lathe 
and turn to shape and dimensions as shown by Fig. 48. 
The shaded portion will be cut out so it will fit down on to 



PLATE WORK AND IRREGULAR PARTING 89 

the pattern already made. The line just above the shaded 
part is the point to cut through so as to coincide with the 
pattern parting. 

To complete this example a core box will be needed, 
which will be made as shown at Fig. 49. The process is 




Fig. 49 

the same as already described, except as to the pieces 
marked X. These are to form a crease or groove in the 
core, to form the babbitt pieces on the casting shown at 
O, Fig. 46. These are simply pieces of wood one -eighth 
inch thick, of a size equal to the cross -section of the 
core box, and with a semi -circle cut in on one side, whose 
diameter is one -inch, that is the size of the shaft the 
bearing is intended to carry. In building the box, the 
pieces must be nailed in between the body of the box and 
the parts forming the prints. The completed box is 
shown at Fig. 49. 

The pattern for a hook lever for Corliss valve gear 
will be the next one taken up. This gives a good exam- 
ple of what is known in the foundry as an irregular part- 



90 



WOOD PATTERN MAKING 



ing, and is illustrated in the chapter on molders' joints 
by Fig. 17, the molders' parting following the heavy 
dotted line. It is also a good example of what may be 
called a built up solid, Onc-piCCC pattern, meaning that the 
completed pattern has no parting. This is typical of a 
very large class of patterns, as all patterns would be 
made Onc-piCCC if they could be conveniently molded in 
that shape. Before commencing the actual work on this 
pattern, notice particularly the position of the molders' 
parting and then the direction of the required draft. The 
first pieces to be gotten out will be the two of which to 
make the arms, each about four and one -half inches 
wide, ten inches long and three -fourths inch thick. 
These should be planed to a true surface on both sides 




Fig. 50. 



to the exact thickness, three -fourths inch, then nailed 
together so their center lines will be at the required angle 



PI. ATE WORK AND IRREGUI.AR PARTING 



91 



of 105°. On one surface of these lay out the shape 
accurately as indicated by the drawing, allowing about 
one -sixteenth inch for draft around the central boss. 
The arms may now]»be sawn out on the band saw, leav- 
ing the marks as a guide for finishing with a file. The 
round boss or disk A (Fig. 50) may now be made. This 
should be sawn out about four and one -fourth inches in 
diameter, one and one -fourth inch plus one -eighth inch 
for "finish" in thickness, and mounted on the lathe and 
turned to exact dimensions , which are four inches in diam - 
eter at B and four and one -sixteenth inches at C, Fig. 50 
(a) . Another boss is needed at D, Fig. 50, but only three- 
eighths -inch thick. These may now be nailed in place on 



kA>| 



k-2 



T 

4" 



r 




5<r 









Fig. 50(a). 
the arms, care being taken as to the side on which each is 
put, as the position of these pieces will determine 
whether the pattern is to be a right or left hand lever. 



92 WOOD PATTERN MAKING 

This can be easilj^ settled by comparing the work already- 
done with the drawing. A screw chuck affords a good 
means for holding these pieces in the lathe, and also the 
stock out of which to turn the four bosses required for 
the ends of the arms. These four may all be turned out 
of one piece by cutting off apiece from a two -inch plank 
about two inches long, measured in the direction of the 
grain, and six inches long, across the grain, and mount- 
ing it in the lathe so that the grain is perpendicular to 
the axis of the lathe. This is plainly shown by Fig. 50A. 
After these bosses are all fastened in place (they should 
be so placed that the grain will run in the same direction 
as it does in the arms) the arms may be shaped or 
rounded into the elliptical form indicated at L, Fig. 50(a) 
and all the different surfaces blended into each other so as 
to make one general even surface. The central hole or 
bore as it is sometimes called, will of course be made 
with a dry sand core, so that it will be necessary to use 
coreprints and a core box. This being a vertical core, 
the shape of prints and core box will be the same as for 
the first exercise, Fig. 38 on page 71. 



CHAPTER XI. 



PUIylvKY PATTERNS 



The next kind of pattern -work to be considered is 
the making of patterns of the general shape of Fig. 32, 
sometimes called annular patterns. The example used 
for the purpose of explaining how such work is done is 
the pattern for an eight -inch pulley with a three -inch 






Fig. 53 



face. The technical description for shop use is written 



like this: Pulley 8 x3 
thick. The "8'' 



hub 2}i^\ four arms, rim ^Aq" 
means the outside diameter of the 



94 WOOD PATTKRN MAKING 



pulley; the 3 " the width of face; 2% " the diam- 
eter of the hub or central boss, through which the shaft 
runs; and **4 arms", the radial arms or spokes that 
connect this central boss with the rim of pulley ; the 
"%6" rim" is the thickness of the rim at its outer edge. 
The finished pulley is represented by Fig. 53. 

The first step in the case of this pattern as of all 
others, is to determine how it is to be molded. As to 
mold it from a one-piece pattern would be quite difficult, 
it is best to make a parted pattern, the parting being 
made on a central plane running through the center of 
the arms; this means that two halves will be made. The 
first thing to do is to prepare a chuck about 9 inches or 
nine and one -half inches in diameter and about one inch 
thick, and face it off true. On this chuck build up a 
ring or hollow cylinder high enough so that both halves 
may be cut from it. If enough is built for both halves, 
it will need to be three inches, equal to the width of pul- 
ley face, plus one inch for cutting off, making in all four 
inches in height. This is to be built of straight -grained 
white pine about seven -eighths inch thick; therefore it 
will take five thicknesses for the required height. These 
pieces will be cut into segments or cants of such length 
that four will complete the circle. They must be cut so 
that the grain of the wood is parallel to the chord of the 
curve. These will be cut on the handsaw or jigsaw, and 
made large enough so that the ring may be turned and 
still allow for draft and finish. As one -sixteenth inch 
is to be allowed for draft and one -eighth inch for finish, 
and as the finished pattern will need to be eight 
and three -eighths inches in diameter at the center, 
the rough built-up ring should be about eight 
and three -fourths inches in diameter. For a guide in 



PUIvLEY PATTERNS 95 

building, make a pencil mark on the chuck while it 
revolves in the lathe so that the circle thus made will be 
of the required diameter. To mark out the segments, 
proceed as follows: Set the dividers at the radius 
required (4^^^) and describe an arc tangent to the edge 
farthest from you of the board from which it is proposed 
to cut the cants. Set the dividers to three and one -half 
inches, and describe another arc; this will leave the cants 
three -fourth inch wide; lay a framing square 
on the board at an angle of 45° with its edge, 
with the heel exactly over the center from which 
the arcs were struck; and at the point where 
the sides of the square cross the arcs, make marks. This 
will give the length of the required segment and at the 
same time give the radial line which is the correct line for 
cutting the cants. If the board is too long to carry to 
the handsaw conveniently, cut off with the handsaw a 
piece just long enough for the segment. Saw out this 
one segment, using it as a pattern with which to mark 
out all the other nineteen cants required. This pattern 
segment should be cut out so that it will be a little too 
long; then the others, when marked out by it, may be cut 
to the mark and still be long enough to allow for fitting, as 
the joints must be exact. Now saw out four more and 
then proceed to fasten them on the chuck. The others 
may be sawn out while the glue is drying. Now a trim- 
mer or shoot board will be needed on which to shoot or 
plane the ends of the pieces. The shoot board and the 
method of its use are shown in Fig. 54. The trimmer is 
a more complicated machine and is represented by half- 
tone on page 97. Plane or trim both ends of one of the 
segments and drive a two -inch brad into it at each end, 
from the top side almost through it; put some glue on 



96 



WOOD PATTKRN MAKING 



the ends and on the under side, and place it on the 
chuck just inside the circle already made, driving the 
brads down until the heads protrude just far enough so 
that they may later be withdrawn with the claw hammer. 
Now fit another segment up to this one, being sure that 
it makes a good joint, especially on the inside of the ring. 




Fig. 54. 
For if a poor joint is made, the small triangular pieces 
formed in cutting the segments v/ill be torn out by the 
chisel during the process of turning. The second piece 
may now be glued into place, being sure as before to put 
glue on both ends and also on the cnd of the piCCC that is 
in place. Thus the ends of the pieces are glued twice, 
which is very necessary if a strong joint is wanted. This 
is called Sizln^ the joint. If it is not done, the first coat 
of glue will be absorbed by the wood and the joint will 
be weak. This course may be followed until the first 
ring or layer of segments is complete, when it should be 





'Oliver'' Trimmers 



PUIvIvEY PATTERNS 99 

allowed to dry. After the glue is dry, the brads may be 
pulled out and the chuck put in the lathe and the ring 
faced off, making it true in both directions. The next 
layer may now be put on in the same way. The ends of 
the cants should be placed about in the center of those 
in the lower layer, so as to break joints. 

The above is the method usually followed in making 
this form of pattern when the cross -section of the ring is 
small, that is, of three-fourths inch, or less. If the ring 
is to be one inch or more thick, it is best to use hand- 
screws to hold the different layers down until the glue is 
dry. If simply a ring is wanted, that is one inch or 
more in thickness, and we are sure there is no cutting to 
be done on it in the future, then the brads may be driven 
clear in and left in the work, except in the first layer. 
This will, of course, obviate the waiting for the glue to 
dry, so that a ring may be built up very rapidly. Zinc 
nails or wooden pegs may also be used in this class of 
work, but if a good quality of glue is used, they are not 
necessary, except in very thin work. The work is now 
ready for the lathe. It is advisable before turning it to 
glue up the stuff for the arms and hub ; then we need not 
wait for the glue to dry, as it will dry by the time the 
rim is turned, unless this is done much more quickly than 
it usually is. 

There are two general ways of building up the 
spider, as it is sometimes called, of a pulley; which is the 
better way is determined by the size, number of arms, 
and some other things. One way is what is known as 
checking the arms together, and then gluing the boss on 
afterwards. This is a good way, if care is taken so that 
they fit exactly. .If they are made too tight, however, 
the ends are likely to be bent out of the correct position. 



100 



WOOD PATTERN MAKING 



This method, of course, cannot be used for spiders hav- 
ing an odd number of arms. A better way for most work 
is to miter the arms together. The only objection to this 
method is that it is comparatively weak. But this defect 
is easily overcome; for, if there is no hub or boss 
required, a recess may be turned into the arms after they 
are glued together, and a piece of haidwood, or metal, 
set in and a screw put into each arm, as shown in Fig. 55. 




Fig. 55. 

If a hub is wanted, and it usually is, this will give the 
required strength. This method maybe used for spiders 
of any number of arms. 

To make the spider, then, for this pattern and in the 
last mentioned way, the first thing to do is to get out 
eight pieces, four and one-half inches long, one and 
three -fourth inches wide, and about five -sixteenths inch 
thick; cut one end of each piece so as to make an angle 



PUI.I.KY PATTBRNS 101 

of 90° at an angle of 135° to each edge. Now saw out 
on the band or jig saw, two disks about three inches in 
diameter, and one and one -fourth inches thick, and glue 
four of the thin pieces on to each disk, with the point of 
the 90° angle directly in the center. The best way to do 
this is to start three one -inch brads, one in each corner 
of the triangle; put on some glue, lay the piece in place 
and drive the nails down, leaving the heads projecting so 
the brads may be afterwards withdrawn with the claw 
hammer or pincers. Now these may be set aside to 
allow the glue to dry. While these are drying, the rim 
may be turned to size and cut off. The chuck, with the 
built-up rim on it, may now be put in the lathe and the 
rim turned to size. The extreme outside diameter should 
be eight and three -eighths inches. This is for the central 
plane through the hollow cylinder. At the ends of the 
cylinder, that is at the point where it is glued to the 
chuck and the opposite or outer end, the diameter should 
be eight and one -fourth inches. These measurements 
must be made with the shrink rule. Before starting the 
lathe, see to it that it will not run too fast. The work 
to be turned should run at a surface velocity of from 
1200 to 1400 ft. per minute for pine wood. This will also 
give very satisfactory results on all ordinary soft wood. 
If the wood is unduly soft, a higher speed may be 
required. It may run much faster than this with safety, 
but it is best to keep the speed down as low as may be and 
still do good work. The work in hand should be run com- 
paratively slow at first, so as to turn off any inequali- 
ties of building, both on the inside and outside; as the 
work becomes cylindrical in form, a higher rate of speed 
may be used. The inside had better be turned first, and 
a diamond -pointed tool will be the best to rough it out 



102 WOOD PATTERN MAKING 

with, using a regular scraper for the finishing. The 
size inside at the center will be seven and three -eighths 
inches diameter; at the two ends, seven and five-eighths 
inches diameter. Finish the outer end back to a short 
distance beyond the center; in other words, back far 
enough to make a little more than one -half of the rim, 
which will be one and five-eighths inches. 

When it has been turned as suggested, it is ready to 
be cut off. lyocate the cutting -off point by holding a 
pencil exactly one and five -eighth inches from the edge, 
while it is revolving; this will make a mark at the 
proper point. Now take a parting tool, and cut into the 
work just outside this mark and almost through, leaving 
a very thin section which may be cut through with a 
knife. It is not good practice to cut clear through, for 
the work may fall on the floor, receiving more damage 
than can be repaired in the time it takes to cut it off 
with a knife. If the work has been done correctly, we 
have one -half of the required rim. As for the other 
half, it is already turned to size at the outer end, and all 
that needs to be done is to turn the rest of it to the size 
and shape of the first one. 

Before being cut off, both of these halves should be 
thoroughly sandpapered, first with coarse, and then with 
finer; No. 2 for the coarse, and No. 1 for the fine are the 
best numbers to use. After they are taken from the lathe 
it is well to give the rims a good coat of black varnish, 
sis it will prevent, to a degree, their tendency to warp out 
of shape. 

The spiders are probably dry by this time, so that 
work can be resumed on them. First, they must be 
planed to a perfectly plane surface on what will be the 
parting in the completed pattern, so that they will exactly 



PUIyLKY PA.TTKRNS 103 

fit each other. Now take the chuck you have just used 
for turning the rim, and face it off to a surface that is a 
very little concave; then while the lathe is revolving, 
make a circle about the size of the disk in the spider. Set 
one -half of the spider on the chuck so that the disk 
coincides with this circle, and drive a brad in two 
of the arms and into the chuck. Before doing this, 
though, it is well to select two one -inch screws, and 
with brace and drill bore a hole through two of the arms 
just the size to fit the screws; these holes should be 
countersunk for the head of the screw, so that they will 
set in below the surface of the arms, to permit of their 
being turned to the proper surface. Now the half spider 
may be set as suggested, and the brads driven far enough 
so that they will hold the spider while the screws are 
being turned in. With the scraping tool face off the 
whole thing in order to true up the faces so that a mark 
can be made, and make a circle on the face of the arms 
equal in diameter to the outside of the rim on the center 
of the pattern. You will notice that this is where the 
arms will finally be joined to the rim. InsldC 
of this circle the arms will be cut down to the 
required thickness (one-fourth inch) , and to the required 
thickness at the hub (five -sixteenths inch). The sur- 
face of the arms should be a straight line between these 
two points. The hub can now be turned to size, (two and 
one-fourth inches), in diameter. There must be a fillet 
in the angle between the arms and hub of about one- 
fourth inch radius. In the center of the hub turn si hole 
about three -fourths inch in diameter, and one-half inch 
deep, to receive a core print. Sandpaper the hub and also 
the arms for a short distance from the hub, taking care not 
to get your fingers caught by the arms as they swing 



104 WOOD PATTERN MAKING 

around. On the arms should be marked a circle whose 
diameter is the same as the inside of the rim at the center 
of the pattern. This circle will serve two purposes, as it 
furnishes a place to space around to locate the center of 
the arms, and also locates the point of tangency between 
the arm and the fillet that must be formed on the arm. 
Another circle should be made around the hub ; this may- 
be about three inches in diameter; the exact size is not 
material. Now this half may be removed and the other 
half put on and treated in the same way, except that the 
two circles last mentioned need not be made. The next 
thing to do is to lay out the lines for the shape of the 
arms. First make a mark that is exactly radial along the 
whole length of one arm, and as near the center as can 
be. Starting from this line, by the use of the dividers 
divide the circle near the outer end of the arms into four 
spaces ; the points thus formed will locate the center line 
of all the arms. Divide the circle that is near the hub in 
the same way, starting from the same line. Set the 
dividers to one -half the width of arms at these points, 
and make marks on each side of these points; these 
marks will locate the sides of the arms ; now with a short 
straight-edge, join the marks by a line along both sides 
of the arms. It is required to have fillets at the intersec- 
tion of the last made lines and the outer circle, which 
may be marked out by setting the dividers to the 
required radius (one -fourth inch), and describing an arc 
that shall be tangent to the straight line and the circle. 
Fillets are also required at the point where the arm joins 
the hub; these should be tangent to a circle about one- 
half inch out' from the hub and to both arms; the radius 
to be such that one arc shall touch all three points. The 
sides of the part of the arms that are set into the rim are 



PULI.KY PATTERNS 105 

now to be located and marked. This is done by making 
a mark parallel with the center line of the arm ; it should 
start from the point of tangency of the fillet arc and the 
circle representing the inside of the rim, and should 
extend to the end of the arm. All of the above 
marks should be on the same side as the hub. 

Next put the two half spiders together so that the two 
hubs shall be exactly over each other, or exactly con- 
centric, and fasten them temporarily by driving a small 
brad through two of the arms. These brads had better 
be put as near the end of the arms as may be. With a 
brace and five -sixteenths inch auger -bit bore holes 
through two of the arms for pattern pins. These pins 
should be located so that they will not be symmetrical with 
the center of the pattern; that is, one should be about 
three -fourths inch further from the center than the other. 
These are now ready to be sawn out, which can be done 
either on the band saw, jig saw, or with the keyhole saw, 
sawing out one half at a time. This will be easy to do 
in the case of the first half, but in that of the other not so 
easy; for, as the second has been marked from the first 
one, the marks will be on the flat side, so that the hub 
will come on the under side. To do the work more 
easily, take a small block of wood with one dimension 
equal to the distance that the hub projects above the arms, 
and set it under the end of each arm as it is being sawn. 
It will be safer to drive a brad through the arm into the 
block, so that in moving it around on the table of the saw 
machine it cannot get out of place. If it is preferred, 
both halves may be sawn at once; but if this is done, the 
pattern pins should first be put in so as to make sure that 
the two halves will be exactly alike, and will set over 
each other just right. After these are sawn out they must 



106 WOOD PATTERN MAKING 

be filed nicely to the lines ; then give them the required 
elliptical form by rounding off the corners and blending 
in all the curves with each other so that a uniform sur - 
face is formed. 

The rims and spiders are now ready to be put 
together. Lay one of the half rims on the bench with 
the side up that will be the center of the pattern, and lay 
on one of the half spiders. If everything has been done 
as directed, they will be self-centering because of the 
extra thickness that was left on the end of the arms when 
turning them. If this has not been done, they may be 
centered by the use of inside calipers, measuring from 
the side of the rim into the hub on three or more sides. 
This should be done very carefully, for if the hub is not 
in the center it will not look very well when the hole is 
bored for the shaft, and of course it will not be balanced. 
When the spider has been correctly located, make a mark 
with a knife on the edge of the rim on both sides of each 
arm ; before taking the spider off be sure to mark one of 
the arms and the place where it belongs, so that it can 
be put back into the same position. Now set a gauge to 
the thickness of the ends of the arms, and gauge a line 
parallel with the edge of the rim between the marks on 
the edge for the recess for the arms. Now saw down to 
this gauge mark and remove the wood, making a nice 
clean gain exactly to lines. Now the arms maybe glued 
and nailed in place. 

The other half should be treated in the same way. 
Before marking recesses, lay them together and notice if 
everything is coming concentric ; if not, you can change 
the position of the second spider slightly, so as to make 
it right. After getting them together in this way, the 
extra length of the arms may be sawn off and the parts 



PULLEY PATTERNS 107 

smoothed up. Two core prints will be wanted for the 
hubs; these, of course, will be tapered because the core 
will be vertical. A coat of varnish should be put on the 
spider, the rim having been varnished before. The 
whole thing is now ready to be finished. First, fill up 
with beeswax any small holes and any other defects in 
wood or work. A fillet is needed on the inside of the 
rim, on the side of each arm of both halves. This can 
also be of wax, put in with a filleting tool of one -half inch 
diameter. Further directions for finishing will be found 
on page 141. To make this job complete, a core box will 
be needed, the same as one described on page 71, (Fig. 
38), except as to dimensions. 



CHAPTER XII. 



PATTERNS FOR CAST GEARS 



The next class of work to be taken up requires the 
greatest amount of care and attention on the part of the 
pattern-maker, as in order to obtain the best results his 
work must be correct in all its details. The class of work 
referred to is the making of gear patterns, especially 
patterns for what are known as Cast §8ars. By this is 
meant, gears of which the teeth are cast to the required 
size and shape, without being cut. There are two gen- 
eral ways of manufacturing gears. 

One way is to cast what is known as a itHT blank, 
which is turned to size and the teeth cut from the solid 
metal. This is the method usually employed for small 
work, and for gears that are required to run very 
smoothly. They are spoken of as a class, as CUt §ears. 

But if the gears are large and of coarse pitch, the 
patterns are made with the teeth of the approximate size 
of the finished teeth. That is, each surface of each tooth 
on the pattern is treated the same as a finished surface on 
any pattern, i. e., about one -eighth inch is allowed for 
finish or machining. After the casting is made, the teeth are 
cut on the gear cutter just as the full blank would be for a 
small gear. Casting them in this way, of course, saves 
an immense amount of cutting, thereby economizing on 
time and the wear of cutters. When, however, only one 



PATTERNS FOR CAST GEARS 



109 



gear of a particular size and pitch is wanted, it is not 
profitable to do this ; in this case the pattern is cut to the 
exact size of the teeth; as in a large class called ''cast 
gears." 

It best serves the purpose of this volume to illus- 
trate some general principles in regard to making gear 
patterns that can be applied by the student to any par- 




FiG. 56. 



ticular case. Consequently, in preference to a gear of 
any specific size, gears of the last mentioned kind will 
be considered. 

The part to be considered first is the rim or periph 
ery of the wheel, to which the teeth are fastened. There 



110 



WOOD PATTERN MAKING 



are several ways that this may be built up ; the difference 
is mainly in regard to the method of holding it in the 
lathe while being turned. The actual building should be 
done as explained for the pulley rim, that is, with seg- 
mental pieces of wood of the required size and thickness. 
As the cross section is of somewhat different shape, the 
segments will of course vary also. If the gear is to be 
large enough so that both sides can be gotten at at the 
same time while running in the lathe, the best way is 
to build up the rim on what may be called a three -armed 
chuck. This is made as illustrated by Fig. 56. 
The width of the arms will be determined by the 




Fig. 56 a. 



size of the gear. For gears up to two feet in diameter, 
pieces seven -eighths inch thick by three inches wide, 
will be heavy enough. The length of the arm will be 
equal to the radius of the rim only. These arms are to 



PATTEJRNS FOR CAST GKARS 111 

be mitered and fastened to a disk a little larger than the 
face plate that it is proposed to use ; the fastening is to be 
done with screws, as indicated. The face plate should 
be put on, and the chuck put in the lathe; then the face 
of the arms, for a distance somewhat more than the width 
of the stock for the rim should be faced -off true. 

It is now ready to have the segments glued on for the 
rim. As will be seen, the first row of segments must be 
made up of three pieces and jointed in the center of each 
arm. After this is glued in place, the rest of the struc- 
ture may be made up of shorter ones, in fact, of any 
length desired. The building process should be con- 
tinued in this way until completed, leaving the arms of 
the chuck as near the center of the rim as possible. 

It is now ready to be turned to size and shape, which 
should be done with scraping tools ; it should be tested 
for shape with a templet. It is not well to cut the arms 
down too thin until the teeth blocks have all been glued 
on and turned to size. In other words, all the turning to 
be done should be completed before cutting into the 
chuck arms very much ; otherwise the rim may spring. 
When all the other turning is done, the arms may be cut 
almost through with very little danger. Of course the 
more nearly through they are cut, the less work will have 
to be done by hand after it is taken from the lathe ; this 
should be left, however, until the tooth blocks are 
glued on and the turning all done. 

The next thing to do is to mark out the spaces in 
which to fasten the tooth blocks. If the pitch of the gear 
is not more than one inch, these blocks may be made of 
such a size that, allowing one for each tooth, they will 
form a complete circumference around the rim. The 
grain of the blocks must be perpendicular to the side of 



112 



WOOD PATTERN MAKING 







O 

M 



PATTERNS FOR CAST GEARS 



113 



the gear, or in other words, parallel with the axis of the 
wheel. They should be made of good, clear, straight- 
grained wood, thoroughly seasoned. 

There are several ways of putting these blocks on 
the rim. Three ways will be explained that will include 
all the practical ideas and principles of this branch of 
pattern -making. In all three, the rim at its present 
stage will be laid out in the same way, that is, spaced 
into as many spaces as it is required to have teeth in 
the wheel. The three ways spoken of will be more 
clearly understood by referring to Fig. 5 7. 

The method shown by the tooth A is what may be 
called the cheap way. In this case the teeth are formed 





Fig. 59. 



Fig. 58. 



before being fastened in place. They may be formed in 
two ways. One is to plane up strips of wood to the 
desired shape, and then cut them off to the required 



114 WOOD patte:rn making 

length. A better way is to make a box as illustrated by 
Fig. 58, each block being cut to exact length and 
held in place by a screw, as shown. Fig. 59 shows 
the method of getting the shape of this box. In using 
this box, care must be taken not to cut away any part of 
it in planing the tooth to shape. To locate a tooth on the 
rim, set the dividers to exactly half its thickness; place 
one leg on the center marks already made, and with the 
other leg make a mark on each side; these marks will 
indicate the position for the sides of the tooth block. Of 
course these marks must be squared across the face of the 
rim so that the teeth may set square. When gluing 
them on use a try -square to test them; do not depend 
wholly on the marks for this. The above method does 
very well for a job where only one or two wheels are 
wanted, and for cases where it is not desired to go to the 
expense of a good job of pattern -making. The second 
way is to glue all the blocks on the rim, lay them out in 
that position, and then cut to the lines. This makes a 
good job when properly done, but it is rather incon- 
venient to cut the teeth, especially if the face of the gear 
is very wide. There is another way that is known as the 
dove -tailing method, so named because each tooth is 
glued to a thin block let in to the rim. One dis- 
advantage of this way is, that if the dovetails are driven 
a little too tight, it is very likely that the rim will be 
sprung, and the resulting casting will not be round. 
About the only advantage claimed for this method is that 
one or more of the teeth may be removed and used by the 
molder for patching up a broken mold ; but this can be 
attained in another way. The method of dovetailing is 
illustrated at B. Fig. 57. It is a very expensive method, 
and is now almost obsolete. 



PATTERNS FOR CAST GEARS 115 

The best way to fasten and form the teeth on gear 
patterns is the one shown in the center of Fig. 57. It 
should be used on all standard patterns. This method 
was first published by P. G. Dingey in the American 
Machinist. Before entering into the details of this way, 
some of its advantages should be noticed. It does away 
entirely with the objection mentioned in connection with 
the dovetailing method, viz., springing the rim by 
driving the dovetails; and at the same time it 
permits that one or more of the teeth be removed by the 
molder, if necessary. Another great advantage gained 
is that the fillets are made in solid wood, thus producing 
a much smoother pattern and casting. None of the 
other methods shown have this advantage. In the dove- 
tailing method a very thin edge must necessarily be left 
at this point. In the first method described a wax fillet 
would generally be used, which in the course of frequent 
use is very liable to be loosened by the shrinking and 
swelling of the wood, leaving the pattern rough just 
where it ought to be the smoothest. Another advantage 
in the method under consideration is that one -half of 
the teeth being fastened on with screws, each alternate 
tooth may be removed, thus making room for working 
those glued on. 

In this method the first thing to be done, after build- 
ing up the rim, is to turn the rim down about one -half 
inch smaller in diameter than the diameter of the whole 
depth circle, or to the point lettered D in Fig. 57. 
Then, of course, the tooth blocks will have to be made 
larger by that amount than the size of the tooth proper. 
After the rim is turned to size it should be spaced as 
previously suggested. This should be done accurately 
so that each tooth may come in the center of each block. 



116 WOOD PATTKRN MAKING 

One set of lines will do if the pitch of the gear is not too 
coarse to allow the stock of which the tooth blocks are 
to be made, to fill the spaces. Otherwise, two sets of 
lines will be required, and pieces must be glued in 
between the blocks, as represented atE, Fig. 57. When 
the blocks are ready and the rim is marked out, one of 
the blocks may be glued in place. Do not get too much 
glue on, as it will be likely to make trouble in putting 
on the next block, for this is to be fastened on without 
any glue. With a brace, and a bit, of the proper size for 
the screws to be used, bore two holes through the rim as 
near the center of the space for the next block as may 
be; counter -sink them on the inside of the rim to receive 
the heads of the screws. Hold the second block in posi- 
tion, and with a brad or small drill mark on the block the 
places for the screws, and bore them with a suitable sized 
drill. Now, holding the block in position again, insert the 
screws, driving them in until the heads are slightly below 
the surface of the rim. This process should be carried 
on until the blocks are all fastened on. Be very careful 
not to glue the blocks together for at least half an inch 
from the surface of the rim, and also not to glue the 
blocks having screws, to the rim, or it will make trouble 
later on. In getting out the blocks for any of the last 
three methods described, they should be made about 
one -eighth inch longer than finished size, and then 
turned off in the lathe so as to make a good smooth sur- 
face on which to lay out the pitch circle, base circle and 
tooth curves, and also on which the spacing of the teeth 
may be done. When the blocks have been glued on and 
allowed to dry, the whole of the work should be put in the 
lathe, the ends of the teeth blocks turned off even with the 
edge of the rim, and the face turned down to the 



patte:rns for cast gkars 



117 



required size. After this is done, a coat of yellow var- 
nish may be put on the parts that are to form the teeth. 
This makes a much better surface on which to make lines 
than does the bare wood. 




A Pitch circle 

B Addendum circle 

C Base circle 

D Whole depth circle 

E Working ciepth circle 

f Radius = l-4th of pitch circle 

Q Radius = l-4th of pitch radius 

M Center of gear 



Fig. 60 
There are several ways of laying: out the tooth curves 
on the pattern. First, however, it must be decided what 
method is to be used for developing these tooth curves 



118 WOOD PATTERN MAKING 

These may be developed by the Bpicycloidal curve, by 
the Odontograph, or by the Involute curve. It is not 
intended in this volume to enter into a discussion of the 
merits or demerits of any one one of these systems, or 
even to explain them, but simply to call attention to them 
and to indicate one or two ways of applying them to the 
pattern. Theoretically, the use of the Odontograph is 
probably the best, especially for large work; but for 
comparatively small work a careful use of the dividers 
will give as good results, and if only single curve or 
involutes are desired, the use of the dividers afford the 
quickest way. In deciding what method of development 
is to be used, one or two further facts should be consid- 
ered. The involute form will give uniform angular velocity 
if the distance between the centers of any two gears does 
not remain uniform, as, for instance, in the feed rolls of 
the common rotary knife planer. Other forms of teeth 
will not do this. Again, if dividers are used for marking 
out these forms on the pattern, the single curve is much 
more quickly laid out. The single curve method is fully 
illustrated by Fig. 60, and is what may be called a simple 
shop method. It can be used to advantage when the data 
supplied by the draftsman to the pattern-maker does not 
indicate any particular method. 

The first thing that needs to be known is the pitch 
and number of teeth. Of course this was learned before 
building up the pattern ; so all that needs now to be done 
is to apply this knowledge to the work. The first line to 
put on the work will be the pitch circle; divide this into 
as many equal parts as there are to be teeth in the gear; 
this is for the purpose of locating the center of each 
tooth. In doing this it will be found advantageous to 
commence at one side of the center of tooth block for the 



PATTERNS FOR CAST GEARS 119 

trial spacing; then having the dividers set to the cor- 
rect distance, start from the center of a block. Then 
there will not be several points to confuse one in fixing 
the correct one for the center of the tooth, as is likely to 
be the case if the centers of the blocks are used for the 
trial division. Now set the dividers to one-half of the 
tooth thickness as derived from Fig. 60 at (a) ;and mark a 
point, one each side of the teeth centers: this will locate 
the sides of the teeth. The base circle (C, Fig. 60) 
should now be put on, its diameter is found as indicated 
by arcs F and G. Now setting the dividers to one- 
fourth of the radius of gear, as at G, Fig. 60, proceed to 
describe tooth curves, being very careful that the arc 
runs through the points located for the side of the tooth 
on the pitch circle. The centers for these tooth curves 
are all on the base circle. At the points where these tooth 
curves intersect the addendum circle (B, Fig. 60), lines 
must be drawn square across the face of the pattern, and 
the opposite side laid out with corresponding curves, each 
curve starting from the point where these squared lines 
intersect the corner. Arcs for fillets at the base of all the 
teeth will now be put in, which will complete the laying 
out of the teeth. 

The next work to be done is to saw out on a band- 
saw, if one is available, the wood between the teeth to 
form the spaces. This should be done very carefully; 
leave one -half of the marks on the work so that there 
will remain very little to be done with chisel and gouge. 
The fillets will have to be made with a small gouge, as 
the ordinary handsaw is too wide to turn in so small a 
curve as is required in small or medium sized work. If a 
gear of coarse pitch is being made, there would be little dif- 
ficulty in making the saw do most of that work also. If 



120 WOOD PATTKRN MAKING 

the teeth were put on the rim as suggested for standard 
work, — that is, if only each alternate tooth is glued on, 
and the others fastened with screws, — then by taking out 
those with screws, the finishing can be done very easily; 
the teeth so taken out should be numbered and cor- 
responding numbers pat on the spaces, so that they may 
be replaced in their proper places after being finished. 
The temporary arms of the chuck may now be cut 
through, thus finishing up the work of making the rim 
and teeth. The shape of this rim may be more clearly 
seen by referring to Fig. 56A. The way of attaching 
the arms also is shown in this figure, as well as in 
Fig. 57. 

The next process is to make the spider, or arms. 
This may be done as described in the making of the 
8 -inch pulley pattern, except that in this case they 
must be made of one thickness and fastened in as shown 
in Fig. 57. 

As these arms are made of one thickness, one 
side will be turned up after the face plate is removed. 
This may be done in a cup chuck shown by Fig. 50, in 
the chapter on Turning. In this case the cup will be 
turned out to fit the hub already turned. The arms will 
be made of the same elliptical shape and in the same way 
as described in the case of the eight -inch pulley. Fig. 53. 

BEVKI. GUAR PATTERNS. 

Before taking up the construction of bevel gear pat- 
terns, it will be well to say something about the lines 
required for laying them out. The first thing is to make 
two lines at right angles to each other, to represent the 
center line of the shafts on which the bevel gears are to 
be fastened. Bevel gears may be made to run shafts at 



PATTERNS FOR CAST GEARS 



121 




Fig. 61. 



122 



WOOD PATTERN MAKING 



other angles than right angles; if this is required, the 
first two lines laid down must be drawn to this angle. 
The next step is to determine the size and the ratio of the 
pair of bevel gears to be made. The pitch diametfer of a 
bevel gear is always measured at the large end. The 
pitch of the teeth is also measured and calculated for 
this end. Having determined on the size of the gear, 
set the dividers to the pitch radius of the gear and prick 
off this, equidistant from line A B, in Fig. 61A, which 
will give the pitch diameter. Now proceed by laying 
down the other lines in Fig. 6lA. Notice that the teeth 
are not developed on the pitch circle, but on a projected 




Fig. 62. 
circle, the center of which is obtained by producing the 
line that forms the end of the teeth back until it inter- 
sects the center line of the gear at H ; the small end is 
treated in the same way, which locates the center for 



^^ 



PATTERNS FOR CAST GEARS 



123 



that end at I. The dimensions of tooth elements may 
be obtained from Fig. 60. The drawing makes it clear 
as to how a bevel gear should be laid out. 

The building of the pattern may now be considered. 
The first thing to do is to select a chuck of proper size, 
if we have one, or make one if we have not. A chuck 
for this purpose may be built as shown by Fig. 62 ; or 63, 




Fig. 63. 

if very large. The rim at A may be left off if thought 
best; but its presence is an advantage if it becomes 
necessary to use handscrews for holding the material on 
the chuck during the process of gluing, for the hand- 
screws may all be set to the same size, and so more 
quickly applied; this is quite an advantage, because the 
glue drys very quickly. The chuck will need to be faced off 



124 WOOD PATTERN MAKING 

to a true surface, and some fairly thick paper glued on the 
part where the segments for the rim are to be fastened 
on. With this exception, the process of building this 
rim will be the same as for the eight-inch pulley. The 
laying -out and the sawing of the cants will also be the 
same, except that each layer will have to be described with 
different radii. The necessity for this will be readily seen 
by consulting Fig. 61B, which shows the rim as it will 
appear after being built on to the chuck, and before it is 
turned. When there has been enough segments built on, 
and the glue has dried, it is ready to be turned to shape, as 
shown by Fig. 61B ; in turning it, get around into the 
work at point P as far as possible. 

It is now ready to be taken off the chuck, which 
can very readily be done by introducing a chisel between 
the work and the chuck, and driving it lightly at several 
places around the circumference. This will cause the 
paper that is glued between the work and chuck to split, 
allowing the work to come off, without any damage to 
either. The rim must now be mounted on the chuck, 
with the opposite side out. The best way to locate it on 
the chuck so that it will be concentric with the lathe 
spindle (as it must be in order that the inside and out- 
side may be concentric), is to turn a small V-shaped 
groove into the chuck that will exactly fit the corner of 
the rim at the point marked R, Fig. 51C. The work 
must be fastened to the chuck this time with screws 
put through the chuck. To do this, bore holes 
through the chuck, at the bottom of the V- groove just 
made, of a suitable size for the screws selected. The 
number of screws to be used will, of course, be deter- 
mined by the size of the work ; from four to six will be 
enough for work up to three feet in diameter. Now take 



PATTERNS FOR CAST GKARS 125 

the chuck off the lathe; and, having laid the rim on the 
bench with its proper side up, lay the chuck on it and 
drive the screws through the chuck into the rim. It is 
now ready for the lathe again, and may be turned to the 
size and shape indicated at points S, Fig. 61C; turn it 
small enough so the tooth blocks maybe put on as indi- 
cated at K, Fig. 61F, and more plainly shown in Fig. 57 
at C C. The arms may now be made, and mitered 
together in the center, with a piece on each side for 
strength; the same pieces also serve as fillets, as indi- 
cated at B, Fig. 61D. The arms should be set into the 
rims as shown at D, Fig. 61D, before the work is taken 
from the chuck. The vertical arms C C, with the cen- 
tral hub E must be left loose so it will lift with the cope. 
These will be built together as shown by Fig. 6lE- 



CHAPTER XIII. 



PIPK FITTINGS 



Another large and interesting class of patterns are 
those required in the manufacture of cast-iron pipe 
fittings, two types of which will now be taken up. The 
castings are what is known as a bend, shown at Fig. 64, 




Fig. 64. 
and an elbow, shown at Fig. 72. The larger part of the 
pattern work can be done on the lathe for both of these 
examples. 

The pipe bend will be taken up first. The first 
thing is to prepare a chuck large enough in diameter; 
turn its face perfectly flat, and glue paper all over it. 

The stock required, as illustrated by Fig. 65, must 
be large enough to contain the size of pattern it is pro- 
posed to build, indicated by the circle on the figure. This 



PIPE FITTINGS 



127 



should be put on the chuck in two pieces, as shown in 
the cut; each half has one side and one edge planed 
straight and at right angles to each other, as the edges 
are to form the joint. These must be so placed on the 




Fig. 65. 

lathe that the joint shall be exactly on the center of the 
lathe. The best way to do this has already been explained 
in connection with core box ends, page 75. They are 
now to be turned to the shape indicated by Figs. 66. The 






Fig. 66. 

next parts to be made are those shown at Figs. 67 and 
68. These must be made in halves and turned. Before 



128 



WOOD PATTERN MAKING 



they are turned, a pattern pin should be put into each, 
so that it will not have to be done after the pattern is 
completed. It is always best to put in these pins before 
the turning is done. After the pieces are turned, the 
parts should be fitted together as shown at Fig. 69. The 





/^ 






k 


ml 


1 1 




ff'"' 


n 


e 

1 









Fig. 67. Fig. 68. Fig. 69. 

part marked (d) should be made square, as shown by 
K,Fig. 68. Of course, both halves are to be made in the 
same way. The core box for this pattern is shown at 





Fig. 70. Fig. 71. 

Fig. 70. The circular part (d) can be made on the lathe ; 
the way is clearly shown at Fig. 71. The grooves 



PIPE FITTINGS 



129 



marked (b) may be made in one piece of lumber, and 
made, of course, with the core box plane. If it is desired 
to make this very strong, a piece of board is nailed on 
the bottom, as indicated at (c). 

As elbows are usually cast in pairs to save work in 




Fig. 73. Fig. 72. 

the foundry, the pattern must be made double. The 
economy resulting is great, as it will take but very little 
more of the molder's time to make the mold for both than 
for one. Besides the core can be more easily set and held 



130 



WOOD PATTERN MAKING 



in place if two are made in the one mold. If only one is 
made, a chaplet would be needed to hold the core; or 
else very long prints would have to be put on the pattern, 
either of which would increase the work of the molder. 
• The pattern for the elbow is a little more complicated 




Fig. 74. 

than for the bend, though the work is quite similar in 
character to that of the last pattern. It is made as fol- 
lows : A ring, as shown at Fig. 73, is first turned, with its 
cross section as indicated at (a). The best way to make 
this is to get out four pieces with the grain as indicated 




Fig. 75. 
in the figure; that is, the chord of the curve should be 
parallel with the grain of the wood. Fit them together 
very accurately, and glue them to a chuck (but not to 



PIPE FITTINGS 



131 



each other) that has been previously covered with paper, 
and turn them to the required shape. A solid piece may- 
be used and cut into the required number of pieces after 
being turned, but this method is not as good. In mount- 
ins: these pieces on the chuck, care should be taken to see 
that the point where they meet is exactly on the center 
of the lathe. Now two pieces are required like Fig. 74. 
These will be made in halves and turned. Both will be 




Fig. 76. 



alike, except that on one the shape at A will be left the 
full size and of a length to equal A in Fig. 75. The one 
made like the figure will be cut in two, the parts B and 
C squared as at E, Fig. 69; it is fitted into the first piece 
as shown at B and C, Fig. 75. 

The core box to go with this pattern is shown at 
Fig. 76. The circular parts A and B can, of course, be 
made on the lathe in the same way as for the core box 
shown at Fig. 70. 



CHAPTER XIV. 



MISCELI.ANEOUS EXAMPLES 



Fig. 78 shows a good method of building patterns 
that are flat, square, or rectangular, and of comparatively- 
thin cross section. The casting required is shown by 
Fig. 77. It is a common form of steam chest cover. In 





Fig. 77. 

building the pattern, the central part is made up of nar- 
row strips set into a groove in the outside pieces ; these 
are mitered together and tongues driven into grooves as 
shown by dotted lines at A, Fig. 78. The diagonal ribs 
made and halved together and then cut to the shape 



MISCEI.I.ANEOUS EXAMPI.es 



133 



shown. They should be left loose and pinned in place 
with pattern pins, so that the molder may take them off 
in order to lay the pattern flat on the molding board dur- 
ing the first operation in molding. This is necessary, as 
in order to have the side B good and sound, it must be 
cast with that side down ; then the ribs will come in the 
cope. 




Fig. 78. 



SKEI.ETON PATTERNS 

The term "skeleton patterns" embraces a large variety 
of patterns; it refers to those that are made of a combina- 
tion of wood and sand; that is, both wood and sand are 
used to form the complete pattern. The pattern-maker 
constructs the required woodwork, and the molder makes 
the rest of the pattern with sand. The sand commonly 
used for this class of work is called loam. 

One example of this class of patterns is shown by 
Fig. 79. It is a skeleton pattern of a pipe bend, from 
which only one or two castings are wanted. The drawings 
give a good idea of the general make-up of the pattern. 



134 



WOOD PATTERN MAKING 



The core and method of making it are shown at Fig. 80. 
The parts the pattern-maker would have to make in order 
that the core-maker could produce this core, are the 
core board, as it is called, indicated by (b) and the 



iB^S^S?^^ 




If! m 



WaiVnit 




Fig. 79. 

strickle shown at (c) in Fig. 80. The core board is simply 
a piece of board planed up true on both sides, and cut to 




Fig. 80. 

the correct shape. Its side (d) is cut in such a way that 
when the strickle is set at right angles to it and slid along 



MISCKI^I^ANKOUS EXAMPI.es 135 

its length, it will give the desired size and shape to the 
core. When the molder uses this apparatus, he first lays 
this prepared core board on an iron plate, and clamps or 
fastens it down so it cannot move. He piles on some 
sand and then slides the strickle along so that the point 
(K) remains in contact with edge (d), taking care to 
keep it perpendicular to the straight part, and to keep 
the cutting edge exactly radial in passing along the 
curved part. If there is any point on the sand that the 
strickle does not touch, more sand is put on and the 
strickle again passed over it. This process is continued 
until a good smooth surface is produced. The core 
board is now removed, and the plate with the complete 
half core on it set into the core oven to be baked. To 
make the other half, the core board is turned over and 
the process repeated. These two halves are baked, and, 
when hard, are pasted together, so forming the complete 
core. The making of the pattern is carried out in a very 
similar way, but requires more work on the part of the 
pattern-maker. The first thing is to prepare two boards 
of suitable thickness for the job; this is determined by 
the size of the pattern to be made. One of these boards 
is shown at (a) Fig. 79. They will be sawn out to the 
shape of the pipe on its axial line, including the core 
prints. 

These boards are pinned together the same as would 
be done if a complete wooden pattern was to be made. 
The flanges (f f) are also to be cut out so that thej^ will 
fit over the board at the correct points. The semicircular 
pieces (dd) are also cut out and fastened on at equal 
distances, and also for the core prints (c c). Two 
strickles will be needed, similar to the one used for mak- 
ing the core, Fig. 80 (c), one for the body of the pat- 



136 



WOOD PATTERN MAKING 



tern, and one for the prints. The molder completes the 
pattern by laying down one of these boards on the bench, 
with the pieces all fastened in place, puts on sand, filling 
up the spaces, and then passes the strickle over it, thus 
making a smooth surface the same as for the core. The 
other half is made the same way. When the pattern is 
complete the molder scatters parting sand all over it so it 
will leave the mold freely. 

Another class of skeleton patterns is illustrated by 
Fig. 81. It represents a pattern for a curved cast-iron 




Fig. 81. 

plate, over which a blacksmith or boiler- maker may bend 
or form a plate of wrought iron or steel. Instead of mak- 
ing a complete pattern, which would be a slow and 
expensive process, a frame is made as shown, and halved 
together at the corners. The rest of the pattern will be 
made by the molder, with the strickle, shown at A in the 
figure. Flat plates of large area may be made in this 



MISCEI.LANEOUS EXAMPI^ES 



137 



way, that is, with the open frame and strickles, thereby 
saving lumber and also a large amount of pattern 
work. A pattern of this kind may be molded by first 
bedding the frame in the nowel, or if too large for that, 
in the floor. Then fill the inside with sand, and strike it 
off even with the top; put on parting sand and then 
ram up the cope. Lift off and set to one side. With a 
strickle cut like A, Fig. 81, with shoulder B the same 
depth as the thickness of the plate, cut out the sand to 
that depth. Now take out the frame or pattern, and there 
is left a cavity in the sand of the size and thickness of 
the required casting. 

GLUING FEATHER -EDGE BOARD 

In building some large patterns it becomes necessary 
to glue on what may be called a feather -ed^ed piece 
of wood, in order to make a shape something like Fig. 82. 




Fig. 82. 

This cannot well be made with solid wood on 
account of the difficulty of guiding a rebate plane along 



138 WOOD PATTERN MAKING 

the obtuse an^le, without the corner of the iron cutting 
into the other side. The best way of overcoming this 
difficulty is to use the method as shown at Fig. 82. But 
this introduces another problem. How can the feather- 
edge be glued on and still be smooth, without a sub- 
sequent planing? Of course the trouble comes from the 
fact that a thin piece of wood on being made wet with 
glue, will, unless held in some way, warp and curl all 
out of shape while drying. A way of overcoming this 
difficulty will now be be described. After having pre- 
pared both pieces to the shape indicated in the figure, 
get out a strip of wood about one -half inch by one inch, 
and long enough to extend the whole length of the 
piece to be glued ; drive a number of brads through it 
about six inches apart. This strip must exactly fit the whole 
length. Now prepare a piece or pieces of good paper about 
one and a half to two inches wide, and long enough to 
extend the whole length. Apply the glue to the feather - 
edge piece, put it in place, and tack it with a brad or 
two so that it will not slip around out of place. Then 
lay the paper on top of the thin feather -edge of the piece 
being glued on, and lay on the strip of wood so that one 
edge comes exactly along and even with the thin edge; 
then drive the brads down, which will pulldown the thin 
edge into place. Examine the feather -edge to see that 
it is down tight to the other piece. If any spots are found 
that are not in contact, put in another nail at that place; 
if this does not bring it down to place, drive a sliver of 
wood under the strip and on top of the paper. The paper 
is employed in this case to prevent the strip from sticking 
to the work, if by chance some glue should get on to the 
upper side of the thin edge. Moreover, if the edge is 
very thin, the glue is very likely to ooze through the 



MISCEIvIvANKOUS EXAMPLEvS 139 

pores of the wood and thus glue the strip to the work, 
and when it was taken off, it would tear up some of the 
wood and make it rough. By interposing the paper, 
this is prevented. 

The work should now be allowed to stand for several 
hours, or until the glue is thoroughly dry. If the strip 
be now removed, it will be found that the feather-edge 
has become practically one piece with the other, and all 
that is needed to finish the job is to sandpaper the 
surface. 

LARGE LATHE CHUCKS 

The method of building a chuck shown at Fig. 
62, on page 122, is very good for one of twelve to 
twenty inches in diameter; but larger ones should be 
built as illustrated by Fig. 63, on page 123. 
Of course the size will determine the number of arms 
required; for chucks up to four feet in diameter, four 
arms of two inches by six inches in cross section would 
be suitable; if larger than that, it would be preferable to 
use more arms, so that the segmental pieces joining the 
arms need not be so long or wide. In building all these 
chucks, each piece of corresponding shape and position 
should be of the same size and weight as nearly as pos- 
sible, so that the chuck will be accurately balanced; 
otherwise, it will be impossible to do good work, and 
besides, an extra strain will be put on the lathe, which 
may cause an accident. If, after building a chuck, it is 
found to be out of balance, it can be balanced by fasten- 
ing a block of wood to the back on the light side. 

LUGS OR PROJECTIONS FOR MACHINISTS' USE 

Some castings must have special parts cast on 
them which serve the purpose of holding them in a 



140 



WOOD PATTERN MAKING 



machine while they are being worked upon, but are 
usually cut off after the machine work is completed. 
These parts it is the pattern-maker's business to provide 
for on the pattern. One form of such a casting is a piston 
ring shown at Fig. 83. The pattern for this should be 




1 




Fig. 83 



Fig. 84 



made large enough so that two to four rings may be 
made from the same casting, leaving plenty of stock for 
finish. A good allowance for this is about one -fourth 
inch on each surface. The reason for this extra allow- 
ance is that these rings being comparatively small in 
cross section, the metal must be very clean and sound to 
give the required strength. As the surface of castings 
is usually more or less porous, it is necessary to turn off 
this outside part in order to get down to the more solid 
metal on the inside. The pattern for a piston ring of 
this size should be made as represented by Fig. 84. The 
projections, c, c, c, called lugs, are for the purpose of 
bolting the casting to the lathe chuck while the rings are 
being turned. This is the usual form in which piston 
ring castings are sent to the machine shop and is the best 
way for this particular job. If these lugs are not pro- 
vided, the machinist has to grip the casting in a chuck; 



MISCELLANEOUS EXAMPLES 



141 



this is liable to spring it, so that the resulting rings will 
not be true, as they must be, to fit the cylinder. Another 
way of providing for the convenience of the machinist is 
illustrated by Fig. 85. Two different methods are illus- 




FiG. 85. 

trated here — one being on the outside of the casting, the 
other on the inside. This casting is the column for a 
small drill press. It is finished the whole of the distance 
A, so it will have to be mounted in the lathe between 
centers. In order that this may be done, there will have 
to be a boss cast on at C and a bar cast in across the round 
opening at B. This latter need not be cut out, 
as it will be entirely hid and out of the way in the com- 
pleted machine. The boss at C may be cut off or allowed 
to remain to suit the fancy of the designer. These are 
examples of simple contrivances to accommodate the 
machinist. 

FINISHING PATTERNS 

After the woodwork of the pattern is completed it 
must be "finished" by the application of one or more 
coats of varnish, all small holes or other defects in the 
material and workmanship filled with beeswax and the 
whole surface made smooth so that it will draw easily. 

This is usually done in the following manner: The 



142 WOOD PATTERN MAKING 

dust from sandpapering is all cleaned off with either 
brush or waste and then a coat of moderately thick 
varnish is evenly applied. When this is dry all nail- 
holes and any defects in material are filled with beeswax ; 
if any wax fillets are to be put in it should also be done 
at this stage. As this first coat of varnish drys it leaves 
the surface of the wood slightly rough ; this is caused by 
the wetting and drying of the varnish which raises the 
grain of the wood. This may now be smoothed down 
by sandpapering it with fine and partly worn sandpaper 
until it becomes smooth to the touch. This is all that 
needs to be done if the pattern is to be used but once or 
twice. If it is to be used frequently one or two more 
coats should be applied. For a permanent finish, several 
thin coats will give better results than one or two thick 
ones, and will also make a better appearance. To make 
a very nice finish each coat should be rubbed smooth 
with fine sandpaper before applying the next. When 
patterns become rough from use in the foundry, or from 
any cause, they should be cleaned and refinished, for if a 
pattern is smooth and well finished it will give themolder 
little trouble and hence will not receive such hard usage. 
If a pattern is rough the molder must rap and jar it con- 
siderable in order to draw it, and such treatment always 
injures wood patterns. In finishing patterns a varnish 
differing in color from that used for the body of the pat- 
tern should be put on all core prints, so that the molder 
can tell at once the general position the cores will occupy 
in the mold. 

I.OOSE PIECES 

It is almost impossible to make some patterns with- 
out loose pieces, however objectionable they may be. 



MlTCELIvANEOUS EXAMPI^ES 



143 



They are, however, in some cases at least, preferable to 
cores. When a choice must be made between a core and 
a loose piece the latter should generally be chosen, as it 
will insure a truer casting. These loose pieces are usu- 
ally held in place on the pattern during the process of 
molding by skewers or draw pins. Brads of suitable size 





Fig. 86. 

for the job in hand and bent to a right angle near the 
head make good draw pins. In some cases it is better 
to fit these loose pieces to the pattern with dovetails. 



144 WOOD PATTERN MAKING 

because when so fitted they are less liable to be pushed 
out of place by the molder in ramming the sand around 
them. Another reason is that the molder does not have 
to stop and take out any skewers, but can go right on 
until the mold is all rammed up. In fact no notice need 
be taken of the loose pieces until after the main part of 
the pattern has been pulled. The best way to fit these 
dovetail pieces is to bevel them on the edges, and also in 
their thickness as shown in Fig. 86. They should be 
fitted very accurately as, if they are not, they are very 
liable to stick when drawing the pattern. The fact that 
they are beveled in both directions as suggested above 
and shown in the cut will almost always insure them 
against sticking. 

STANDARD PATTERNS 

Standard patterns made of wood, and often used, 
should be made as durable as it is possible to make them, 
using hard wood, such as Mahogany or Cherry, for all 
the parts that come in direct contact with the sand. For 
all parted patterns metal pattern pins should be used, 
brass being the best. The first cost is more, but time 
and labor required for applying them is less, and most 
important of all, they never stick, if properly fitted at 
first, so that in the ''long run" they are the cheapest; 
and standard patterns are usually made for the ''long 
run." 

Rapping and draw plates should always be fitted to 
all standard patterns, as they will save their cost in repair 
work in a very short time, to say nothing about the con- 
venience of the molder. There are several kinds of these 
plates on the market at very reasonable prices. For any- 
thing except very large patterns, plates combining both 



MISCKLI.ANKOUS EXAMPLES 145 

rapping and drawing holes are the best. The rapping 
holes in these plates are simply drilled, drawing or lifting 
holes are taped to fit some standard screw thread. 
Another method of preparing standard patterns for the 
foundry is to fit them to a folIOW board. This is almost 
always done when a large number of castings are wanted 
off from a pattern that requires an irregular parting, or if 
the pattern is thin in cross section and is liable to be 
injured by ramming the sand around it. The cope side 
of the pattern is fitted to the top side of the board down 
to where the molder will make his parting, and the board 
cut to such a shape as will form the parting. This 
follow board is used the same as a turn over or mold- 
ing board in molding a simple pattern. 

STOVE PATTERN -MAKING 

The fundamental ideas underlying the making of 
patterns for stove castings are practically the same as 
for machinery pattern -making; but on account of the 
shape and generally delicate character of the castings 
required, the methods of their production are in many 
respects quite different. The drawings furnished the 
stove pattern-maker are also radically different from 
those sent to the maker of machinery patterns. Gener- 
ally a new design of a stove is first developed by making 
a drawing, and, at the same time, a model is also worked 
out in wax or clay, and in some cases a complete model 
is made of wood. 

This gives the designer the opportunity of compar- 
ing curves and other ornamental features of the finished 
stove which is impossible from drawings alone, and 
enables him to see how it will be best to have the different 
parts fit each other at the many joints necessary. This 



146 WOOD PATTERN MAKING 

is especially advantageous in the case of artistic heating 
stoves, on which there is usually a large amount of carv- 
ing. A model, however, is not generally made in the 
case of plain work, such as cook stoves or ranges, these 
being carried through from drawings alone. There are also 
several tools that are used by the stove pattern-maker 
that are not used by others. These are made necessary 
by the requirements of the art; one of which is that the 
castings, and therefore the patterns, must generally be of 
uniform thickness, and comparatively thin in cross sec- 
tion, usually not exceeding one -tenth of an inch. 

Almost all machinery pattern drawings are made 
and all dimensions given in finished sizes so they may 
be used in the machine shop as well as in the pattern 
shop. Stove pattern drawings seldom go farther than 
the pattern shop. They are usually made full size and 
in some cases at least, the dimensions are not marked on 
them, so that the pattern-maker must take the sizes 
directly from the drawing by measuring it, and this is 
usually done with trams and applied to the shrink rule 
to be used. The plan is first drawn and then the eleva- 
tions or side views are drawn in, usually on the same 
paper so that the lines of each view are all mixed up, 
which makes the reading of them very difficult for those 
unfamiliar with this kind of work. Sometimes the lines 
of these different views are made with different colors, 
so as to be the more easily read. The same shrink rule 
to be used in making the original patterns is used by the 
draftsman in making these drawings. 

The stove wood pattern-maker is provided with 
from five to seven different shrink rules ; the one to be 
used for any given pattern is determined by the kind of 
metal of which the master pattern is to be made and also 



MISCKLLANEOUS KXAMPLKS 147 

the method of producing it. These rules are spoken of 
as one shrink, two shrink, or one and a half shrink 
according to the ratio of the rule to the standard rule. 
The word "shrink" in this instance meaning the general 
amount allowed in making machinery patterns, viz: one- 
eighth inch. Which one of these is to be used is de- 
termined by the material to be used in the production of 
the master pattern. 

Because of the necessity of beveling the edges of all 
stove plates where they come together, and to have 
these bevels uniform throughout the stove, it has been 
found advantageous by stove pattern-makers to have a 
set of "bevel gauges" for measuring and laying out these 
bevels. Such a set of bevel gauges was originated by 
Mr. N. Vedder, formerly a stove designer of Troy, N.Y., 
and which have come into extensive use among stove 
manufacturers during the last few years. In order that 
these gauges may be convenient for use, they are made 
of thin wood or metal similar to the triangles used in 
making mechanical drawings. There are eight of these 
bevels in use ranging from one of about 2° to that of 30°, 
which is the largest angle used. These are numbered as 
follows: From two degrees to eight degrees are four 
bevels numbered by ciphers, two degrees being desig- 
nated by 0000, the next by 000, the next by 00, and the 
next by 0, which is eight degrees. The other four bevels 
are designated by the numerals 1, 2, 3,4, number one 
being an angle of 10°, number two, 16/^°, number three, 
23/^°, and number four, 30°. As in a large part of stove 
patterns it is necessary to make them of curved outline, 
and as these curves cannot very well be marked out 
with trams, a set of standard curves have been adopted. 
These are used by having them made up of thin wood or 



148 WOOD PATTKRN MAKING 

metal (metal being best) so they may be used in the same 
way as the bevel gauges. These are likewise used by 
both draftsman and pattern-maker. 

It sometimes becomes necessary to make a center 
line across a carved or other uneven surface. For this 
purpose a simple contrivance known as a "vertical 
plumb" has been devised. It consists of two boards 
fastened together lengthwise ''at their edges and at right 
angles to each other. This must be set up on two par- 
allel blocks of such a height as will raise it above a pat- 
tern or other object on which it is required to make a 
straight line across the uneven surface. A scriber with 
which to make the mark is also needed. This consists 
of a thin flat piece of wood on which is fastened a thin 
plate of steel sharpened to a keen cutting edge. 

Stove patterns must be carved very thin and made 
of uniform thickness throughout. If they are not the 
castings will not be of even thickness, so that one part 
will cool more rapidly than others, thereby causing them 
to warp and sometimes to crack from the shrinkage 
strains. To insure that the patterns are of unifoim 
thickness, a special form of calipers are used for meas- 
uring their thickness. These calipers are made with a 
loose joint something like a pair of shears. Just at the 
back of these shear-like handles are short projections, 
through one of which a screw is put, the end of the screw 
abutting against the other. The points of the caliper 
may be set to a definite distance apart, the above screw 
turned in until its end comes in contact with the other 
projection mentioned. The calipers may now be 
opened and passed over any intervening thick part of a 
pattern and the points closed again to the same distance 
as before. Now if the screw does not touch, or come to 



MISCKIylyANEOUS KXAMPI^KS 149 

a bearing, the pattern is too thick at that point and must 
be pared down. Most stove plate work is very uneven 
on the surface on account of the carving and other orna- 
mental work. In order that the pattern may be of equal 
thickness it has to be "backed out," as it is called, that 
is, it has to be carved out on the back to conform to the 
shape of the carving on the front. This makes it neces- 
sary that the outlines of the carving be transferred to the 
back. This is most easily and accurately done by the use 
of what are known as "marking calipers." These are 
usually made of hard wood and similar in shape to the 
ordinary wing caliper that is hinged together at the end 
of what may be called the handle. One leg is provided 
with a steel point, the other with a pencil point. A 
spring is set in between the two parts of the handle that 
tends to open the points, so that in order to bring the 
points together this spring must be compressed. By fol- 
lowing the outline of the carving with the steel point, 
and at the same time compressing the spring and keeping 
the pencil point in contact with the back of the pattern, the 
outline may be accurately and rapidly transferred to that 
side. Many parts of stove patterns have to be joined on 
an angle, and as the stock is generally very thin, it is 
quite difi&cult to joint the edges to the correct angles, 
therefore it is necessary that some device be provided 
for holding the stock in fixed position with regard to the 
plane. For this purpose some form of shoot board is 
found useful. One form of shoot board is represented 
by Fig. 54 on page 96. For stove pattern work, how- 
ever, it must be more complicated than is this, as it is 
necessary that it be adjustable to several different angles, 
and be set accurately to any given angle within its lim- 
its. As a large amount of carving is necessary in stove- 



150 WOOD PATTERN MAKING 

pattern -making which cannot be done with the chisels 
and gouges of the ordinary pattern-maker's outfit, the 
stove pattern-maker is provided with a series of carving 
tools, usually about twenty in number. In large estab- 
lishments making stove -patterns, the carving is usually 
done by men especially skilled in that work, and in some 
cases stove -patterns pass through the hands of several 
men, each doing his own special kind of work. A large 
quantity of very thin stock, some of which is less than 
one -twelfth inch in thickness is required for this 
class of patterns. As this cannot very well be 
made on the ordinary planer without some special 
attachment a suitable one is provided for the planer in 
stove pattern shops with which thin boards may be 
planed smoothly and to a uniform thickness. 

Almost all machinery patterns are fairly thick and 
stiff enough of themselves for the purpose of molding; 
moreover, in the production of this class of patterns, the 
application of the principles of joinery is an important 
part. Stove patterns are usually very thin, and practi- 
cally of uniform thickness throughout and therefore 
require special treatment. Stove patterns are rarely stiff 
enough of themselves for the purposes of molding and 
must be supported by what is called a "match" during 
the process of molding to produce the metal patterns. 
The match is very frequently made first and the pattern 
made or built on it. In many cases these patterns are 
very intricate having quite a large amount of carving on 
them. 

Because of these many facts, stove pattern -making 
differs considerably from ordinary pattern -making and 
is a distinct branch of the art. The original pattern for 
stove work is usually made of wood; in some shops, 



MISCEIvIyANKOUS EXAMPI^KS 151 

however, original patterns are sometimes modeled in 
clay or plaster -of -Paris. From this original pattern a 
master pattern is made of iron. For this purpose, how- 
ever, some foundries use a white metal alloy consisting 
of nine parts lead and one part antimony, which has a 
shrinkage of one -sixteenth inch per foot. This is pre- 
served and from this the pattern to be used in the pro- 
duction of the castings for the stoves is made. The 
original wood patterns are rarely kept as they are sure to 
change their form. There are several distinct processes 
used in making stove -patterns, but on account of space 
they cannot be described and will for that reason be just 
barely mentioned. One of these is what is known as the 
"carving and backing out wooden patterns." This is 
the simplest, and means that the pattern is carved out of 
wood to the exact shape and thickness. For a small 
pattern, like a stove leg for instance, this would be all 
that is necessary from which to make the mold for the 
master pattern. For large patterns in this process, how- 
ever, a match or follow board must be made to support 
the pattern while ramming up the nowel. Another dis- 
tinct process is the "wax process." This is used to 
avoid backing out the wooden pattern. Considerable 
practice or experience is necessary to work this method 
successfully. Then there is the "carving and blocking" 
process, in which the molder surrounds the pattern with 
a thin layer of blocking just the thickness of the required 
casting, when ramming up the drag. In all these pro- 
cesses the block of wood used for the pattern is "built 
up" of thin pieces of wood, so as to reduce the effects of 
shrinking and swelling to the minimum. In many stove 
patterns allowance has to be made for the warping of the 
casting. This is usually done by preparing a special 



152 WOOD PATTERN MAKING 

form of mold board which is curved so as to give the 
required curve to the pattern, as it is built on to and over 
the mold board. This is necessary because a casting 
made from a straight pattern often comes out warped or 
bent so that it is necessary to bend the pattern in the 
opposite direction, so that the casting will come out 
straight. 



Appendix 



READING MKCHANICAI, (wORKINg) DRAWINGS 

Mechanical drawing has been defined as the univer- 
sal "language of the engineer." A drawing made in 
one country can be read and worked to in another, that 
is, the drawing proper. Notes on the drawing in the 
language of a country could not be read except by one 
acquainted with its language; and, the unit of measure- 
ment also might be different, but the main idea repre- 
sented by the drawing would be readily apprehended. 

One who desires to read working drawings and get 
from them the information they are intended to convey, 
must know something of the principles underlying their 
construction, and the conventionalities used. All work- 
ing drawings are made on the principle of orthographic 
projection, usually spoken of simply as projection draw- 
ings. That is, ail the imaginary lines of sight, (projec- 
tors I , are parallel, and perpendicular to the picture plane. 
There are three principal VicWS, or elevations, as they are 
called, used in the representation of objects by drawings, 
viz. : the plan, or top ViCW, and Cnd or SidC VlCW, called in 
descriptive geometry the three planes of projection. It 
is sometimes necessary to introduce a fourth ViCW, which 
becomes a SCCOnd cnd OF sidC ViCW. Each of these views is 
drawn so as to represent the different sides of the object 
at right angles to each other. When some parts of an 
object extend at an angle other than a right angle, 



APPENDIX 155 

auxiliary views are projected on the center lines of these 
angular parts, in order to show their true shape. In the 
representation of simple or symmetrical objects, one view 
is omitted, usually the plan, as it is not necessary. 
Many objects or parts of machinery, (with which the 
pattern-maker has most to do), can be represented with 
sufficient clearness by two views. When these do not 
clearly delineate the object, the third, and if neces- 
sary a fourth is used. 

The obscured parts of a simple object, that is, parts 
that do not appear on the surface represented, are shown 
by broken lines. In complicated objects this is not 
practicable because of the many lines that become neces- 
sary, which would be confusing and lead to mistakes. 
When for this reason this method of broken lines is not 
feasible, it is customary to imagine the object cut, or 
that an assumed plane has been passed through it, and the 
surface thus produced exposed. A drawing of such a 
surface is called a SCCtion, and indicates the shape of a 
piece at the place cut by an imaginary plane. A piece of 
varying section may be cut by planes at as many places 
as is desired, and the section shown at each. Complete 
sectional views show not only the parts cut by this 
assumed plane, but also any other parts of the object 
which may be seen beyond. Such sectional views are 
usually made by passing a plane through the line of 
centers, or other line of symmetry. To indicate the cut 
surface of a section it is filled with uniformly spaced 
diagonal lines. This is called croSS-hatchJn^. Different 
pieces of material appearing in the same section are indi- 
cated by the lines running in different directions. Dif- 
ferent materials are indicated by using different kinds or 
grouping of lines. An incomplete section shows the 



156 WOOD PATTERN MAKING 

objects partly in full elevation, and partly in sectional 
elevation. Such drawings are also called broken draw- 
ings. I^ong, symmetrical parts, as a piece of shafting, 
may be shown by making drawings of the ends close 
together with the middle portion broken out. These 
are also called broken drawings, and are used to save 
space or to get a long piece on a small sheet. 

Various arrangements of views on a drawing are 
possible, each of which will be equally effective in 
conveying the necessary information. Attempts have 
been made to establish uniformity of practice in this 
respect, withoat effect, for the reason that such a vast 
variety of forms are encountered, and difficulties of 
execution are met in practical work, that in general it is 
not possible to follow any cut and dried rules. When 
making drawings for use in engineering construction, 
especially for workshop use, that draftsman is the best 
one who can convey the necessary information with the 
least expenditure of time and labor spent in making the 
drawing, consistent with neatness of execution and 
accuracy of dimensions. About three things must be 
kept in mind in making or interpreting a drawing. 

First — Bach view of the part of machine or structure 
represented must be a projection of the adjacent view of 
the same object. 

Second — It must be clear which end or side view is 
shown in the adjacent view, whether it is the end or side 
nearest the adjacent view, or the one farthest from it. 

Third — In the case of unsymmetrical parts it is neces- 
sary to be sure whether the piece to be made is "Right 
hand" or "Left hand." 

These last are shop terms that have originated in 
practice, and may be illustrated by considering a photo- 



APPENDIX 



157 



graph and its negative. An object appearing on the right 
side of the photograph will appear on the left side of the 
negative, and the whole picture is reversed. Suppose 
the pattern being made is curved on one side and straight 
on the other, we must be sure which side is straight and 
which curved. 

A good general method of procedure in reading a 
working drawing is as follows: First, ignore for the time 
being the dimensions and dimension lines entirely until 
an idea is obtained and fixed in the mind of the general 
shape of the object. Second, refering to the several 



A 



G 






M 



i^j-. 



A 



2t 



^^ 



jcj 


M^;±^ 



Fig. 1 (d) 

views, notice if its outline is to be a cylinder, a cube, a 
cone, etc., or a combination of several of these element- 
ary forms. This being clearly impressed on the mind, 



158 WOOD PATTERN MAKING 

observe how it is modified by details, and, always refer - 
ing to the several views, determine whether they project 
from the main body, or are recesses or holes. Finally 
form an idea of the relative sizes of the component parts 
by refering to the dimensions. Pay strict regard to all 
conventional representations that have been used. 

At Fig. 1 (d) is shown how the views are usually 
arranged when three views of an object are given. This 
arrangement may be modified when some other will bet- 
ter convey the meaning. If still another view was 
thought necessary to represent the object as it would 
appear when looking at its left side it would be located 
at the left of the front view ; this would be called the left 
side view. In the drawing, "A" is the plan or top view, 
**B" is the front view, and *'C" is the right side view. 
These names are purely arbitrary and are used only as 
conventionalities, as any side of the object may be 
assumed as the front view except when the object has a 
natural base, as a table, or a machine, etc. Then the 
top view would be a drawing of the top side of the 
machine as it stood in its normal position, that is, on its 
natural base. 

One good way of determining the shape of an object 
from a drawing is to imagine the paper on which the 
drawing is made to be bent on a line somewhere between 
two of the views until the surfaces are perpendicular to 
each other, or actually bending the paper with the draw- 
ing on it in this manner, then imagine some object that 
if projected on the two planes would give outlines like 
the ones shown on the drawing, treating sectional views 
in the same manner as full views. 

On page 159 is introduced a working drawing of the 
headstock of a lathe. It illustrates several of the pre- 



APPENDIX 



159 




160 



WOOD PATTERN MAKING 



viously mentioned conventions. One of these is the 
arrangement of the views, which is different from that of 
Fig. 1 (d). In Fig. 2 (d), the plan, (A) is below the 
front view (B), therefore the front view shows the side 
of the plan that is the farthest from it. In Fig. 1 this is 
reversed; but this does not interfere with the interpreta- 
tion of either, as when any one of the views is studied 
with relation to the others the form of the object can be 
readily imagined. 

What is known as a "broken drawing" is also illus- 
trated in this figure at D and D. In this case one -half 



1 *^ I 




Fig. 3 (d) 

of the object is supposed to be broken away, and a view 
given as the object appears at that point after its removal ; 
this makes it easily understood as to the desired shape. 
Another convention illustrated is the method of indicat- 
ing which surfaces are to be machined. It is by the use 
of the letter F, placed on or near the surface to be 
machined or finished. One method, (broken lines) of 
indicating the location and size of tapped holes for the 



APPENDIX 161 

reception of bolts is also shown in the center of each 
bearing. Fig. 3 (d) shows one way of representing 
simple circular objects that is used quite frequently in 
machine drawings. The sectional view is a complete 
section. 

LUMBER 

Lumber is produced by sawing trunks of trees 
lengthwise into planks or boards of commercial sizes. In 
order to produce special sizes and shapes, the sawing is 
done in several different directions without regard to the 
grain of the wood. There are, however, two general 
directions or methods used, by one or the other of which 
the larger part of all lumber is produced. One of these 
is called Straight or bastard sawing; the other quarter saw- 
ing. Straight sawn lumber, sometimes called "rift 
sawn," is produced by passing the saw through and 
through the log, without any regard to the grain. Quarter- 
sawn lumber is made by passing the saw through the 
log approximately parallel with the medullary rays, or 
radially with the log. There are several ways of doing 
this, one of which is as follows: The log is first squared 
and then sawn into four quarters. Each one of these is 
set on the carriage of the sawing machine so that the saw 
will pass through it diagonally. The sides of the center 
board will then be parallel with the medullary ray. 
This method gave rise to the term "quarter sawn." 
The larger part of the lumber produced is made by 
the first method. The last is very wasteful of timber, 
and the product is therefore much more expensive. 

If the trunk of a tree is cut transversely, it is found 
to be composed of a series of concentric cylindrical lay- 
ers, the cross sections of which form rings that are quite 



162 WOOD PATTERN MAKING 

distinct from each other. These layers are formed, one 
each year during the period of the tree's growth. They 
vary in thickness in different kinds of wood, and in dif- 
ferent specimens of the same kind. They also vary in 
density and color; the more dense or hard are always 
found near the heart. These variations are due to the 
difference in rapidity of growth, length of season, and 
other circumstances that may change from year to year. 
The location and soil in which the tree grew also modifies 
to a degree the above characteristics of these layers. It 
is these layers of woody fiber that give to boards the 
appearance called "the grain." This appearance varies 
according to the position the board occupied in the log. 
The part of the wood next to the bark is called **sap 
wood" ; all on the inside of this is called "heart wood." 
Heart wood is generally more dense, of a darker color, 
and is much more durable than sap wood. During favor- 
able weather the sap of the tree circulates through the 
sap wood, but during the winter it is supposed to cease; 
it is this period of non- circulation of sap that causes the 
distinct lines that appear between successive annual rings. 
The darker color and greater density of heart wood is 
caused by the closing up of its cells by the gums of the 
wood that were previously held in solution ; for this 
reason it is nearly or quite impervious to sap. There is 
a difference in the proportion of sap wood in different 
kinds of trees, and in different individuals of the same 
species. The slower growing trees usually have the 
least. 

For a tree to afford the best quality of lumber it 
should not be cut until it has arrived at maturity. The 
oak is said to reach this period in about 100 years, the 
pine in 70 to 100 years, and ash and elm at from 50 to 



APPENDIX 163 

100 years. Midwinter or midsummer are the seasons of 
the year best adapted for the felling of timber to secure 
the best quality of lumber. The principal reason for this 
is the fact that at these seasons the trunk of the tree con- 
tains less sap than at others. 

Seasoning lumber is driving OUt tllC Water from its pores. 
This may be done by natural or artificial means. However 
it is done it should be a slow process, especially in its first 
stages, therefore, natural, or air seasoning, gives the best 
results. For any purpose where strength or permanence 
of form is very desirable, it is best to properly "stick 
up" the lumber in a seasoning shed that will protect it 
from the sun, rain, and snow, for at least one year, and 
then put it in a drying kiln to complete the process. If 
lumber is put into the kiln when green, the water is 
driven out so rapidly by the high temperature that it car- 
ries with it more or less of the gums of the wood. This 
is prevented by "sticking up" in the shed, as during the 
time it is under these natural conditions the process is 
comparatively very slow. All these gums should be retain- 
ed, if possible, as they add strength and density to the lum- 
ber, and the more dense wood is, other things beingequal, 
the more permanent will be its form under varying con- 
ditions of the humidity and the temperature of the sur- 
rounding atmosphere. Conversly, then, if these gums 
are driven out during the process of seasoning, the wood 
is not as strong, and is more porous, also, and will 
therefore absorb and give off moisture more readily, 
which will interfere with its permanence of form. Lum- 
ber cannot be so well seasoned as not to shrink when 
placed in a dryer atmosphere. 

If wood is placed in air that is quite dried of its 
moisture, it will continue to retain a portion of its 



164 WOOD PATTERN MAKING 

original moisture. A log taken from a freshly cut tree 
(green) contains about 50 percent, by weight, of water. 
(The sap wood contains more than this percentage, the 
heart wood less). When the log (stripped of its bark), 
is allowed to remain in the open air, more than half of 
this water will evaporate in a few months. If it is sawn 
into lumber and "stuck up" in a seasoning shed, the 
water will be further reduced to from 12 to 15 per cent, 
of the total weight; if it is put into an ordinary living 
room it will be reduced to from 8 to 10 per cent. ; if it is 
put into a drying kiln operating at a temperature of from 
160° to 180° F., only from 2 to 4 per cent, of water will 
be left ; but though the temperature be raised to 300° 
F. (when chemical destruction begins), water will still 
be given off. Immediately after wood is taken out of a 
kiln it begins to absorb moisture. In a week it will 
have regained from 5 to 6 per cent, of moisture; in a 
month or so, its condition, if kept in the open air, will 
be normal — that is, 12 per cent, of its weight will be due 
to the water it contains. Whenever wood gives off 
moisture it shrinks. Green wood will by seasoning 
shrink about 8 per cent, of its width across the grain. 
One of the objects of seasoning is to reduce the moisture 
to the proportional limit that will obtain between the 
wood and the air with which it will be surrounded after 
it is manufactured into some article of use or ornament. 
Neither air seasoning nor kiln drying at a temperature 
below 200° F. , will affect the capacity of wood for taking 
up moisture when there is an excess of humidity in the 
air, and whenever wood takes up moisture it increases 
in size (swells). 

This faculty in wood of resuming original size, of 
being larger or smaller, according to atmospheric con- 



Appe)ndix 165 

ditions, is one of the most difl&cult problems with which 
wood -workers have to deal. To paint wood -work, or to 
varnish it makes little difference to these qualities ; these 
coatings simply retard these changes, they do not over- 
come them. For these reasons, whenever it is required 
to cover large areas with wood -work, some method must 
be adopted to nullify the effect of, or of concealing 
altogether, the "working" of the various pieces of wood 
after they are placed in position. The combined precau- 
tions of intelligent framing, and the application of pro- 
tective coatings fail to secure immunity from these 
hygroscopic effects. Wood is doubly affected by the 
cold, damp air of the winter months. By the natural or 
air seasoning process, two years for small or thin, and 
four years for large or thick lumber is necessary to 
secure good results; lumber is, however, rarely over- 
seasoned. It may be much more rapidly seasoned by 
high temperatures in drying kilns. It is not impossible 
to season one -inch thick boards by this means in two 
days, but it ''kills the life" of the timber. As a rule, 
the softer a wood is, the more readily it will shrink or 
swell. Great care should be taken in preparing the 
foundation on which to pile lumber for the purpose of 
seasoning it. The edges of the timbers on which the 
boards are laid should all be in the same plane, so that 
the boards (which will retain the shape given to them 
by the pile) , may be true planes when taken out of the 
pile after seasoning. 

Warping in wood is a chan^C Of form result- 
ing from unequal shrinking or swelling. It is 
sometimes caused by unequal exposure; in fact this is 
its most fruitful cause. When a board is so placed as 
that one side is exposed to the direct rays of the sun or 



166 WOOD PATTKRN MAKING 

Other heat, and the other to a damp atmosphere, the 
first side will become concave. A board, especially a 
green one, will also warp when it is equally exposed, 
that is, when it is surrounded by equally dry air. The 
cause of this is, that the board, because of the arrange- 
ment of its cells, gives off the moisture it contains more 
rapidly from one side than the other. The side that dries 
first will become concave. Now if a board is cut from a 
log midway between the heart and sap, there will be a 
larger number of the cells, (which lie parallel to the 
sides of the annual layers), opened on the sap side; 
therefore, moisture will be given off more rapidly from 
that side, and, as wood always shrinks when it gives off 
moisture, that side will shrink first and become concave 
and the heart side convex. The medullary rays, as they 
shrink, also conduce to this form in a slight degree. 

If these facts are kept in mind, and the end of a 
board is examined it may be known in what direction 
the board will warp, when any of the above conditions 
obtain as to its surroundings. Quarter -sawn lumber is 
cut radially to the log, and so does not contain these 
characteristics, therefore will not warp much. 

From these facts, then, the following principle may 
be deduced: In all wood work, the heart side of the 
board should always be placed on the side of the work 
that will be the most exposed to any change that is likely 
to take place in the surrounding atmospheric conditions, 
for the reason that it is the least susceptible to change 
of the two sides. 

Because of the above noted characteristics of wood, 
it is best to cut the pieces to be used in any construction 
roughly to size, and allow them to stand for some time 
before they are cut to the finished size. If this is done. 



APPENDIX 



167 



they may warp into a more permanent form, and so will 
be less likely to change the form of the final construc- 
tion. A board that has recently been planed to a true 
surface should not be left lying flat on the bench, as it 
will warp and become concave on the upper side. This 
is due to the greater exposure of the upper surface com- 
pared with the under, which remained in contact with 
the bench. A board having reasonably straight grain, 
and which has been planed to a true surface all over, 
should be left on its edge or end. 

TOOLS FOR BENCH WOODWORK 

For all hand wood work the bench is the first 
requisite. The best form of bench for pattern -making 




Fig. 1. 



is that illustrated by Fig. 1. If this is fitted with a No. 
1 "Emmert" Pattern- Maker's Universal Vise, shown by 



168 



WOOD PATTERN MAKING 



Fig. 1 (a), instead of the one shown at the head of the 
bench , it will be the best that can be obtained for this part of 




shop equipment. Thebcnch hOOR is a very useful part of 
bench equipment, one form of which is shown at Fig. 
2 ; it should be twelve to fourteen inches long. Some 
form of saw -horse is also a necessary part of pattern shop 




Fig. 2. 



equipment; a handy and easily built form is shown at 
Fig. 3. Another almost indispensable article, something 
like a bench in its nature, is what is known as a laying 
out tabic, or large drawing board, on which work can be 
laid out at full size when necessary. it should be built 



APPENDIX 169 

very solidly, and have a top that is a true plane. This 
will be found very convenient on which to build some 
classes of patterns, for by using this they may be built 




Fig. 3. 

up over the lines laid out, as is sometimes necessary. In 
some shops this laying out table is of iron, with the top 
planed true. 

MKASURING AND LINING APPIvIANCKS 

The standard of length used by mechanics and 
engineers in the United States is the English yard. The 
standard for reference is the "Troughton Scale,'' a 
bronze bar with an inlaid silver scale, made for the coast 
survey of the United States, by Troughton, of London. 
This was adopted as the standard by the Treasury 
Department in 1832, on the recommendation of Mr. 
Hassler, who was at that time the superintendent of the 
United States Coast Survey. The mctcr has since been 
made the legal standard ; the act of Congress making it 
such was passed in 1877. The most commonly used 
measuring appliance, however, is what is known as the 
two foot rule. This is a strip of wood, usually boxwood, 
twenty -four inches long, and about half an inch wide. 
For convenience in carrying, it is jointed so that it can 



170 



WOOD PATTERN MAKING 



^ 



be folded into two or four folds. These rules for general 
wood workers' use are graduated in 
sixteenths of an inch on one side and 
eighths of an inch on the other. The bet- 
ter class have the inside of each leg gradu - 
ated in lOths and 12ths of an inch. 
(See Fig. 4). Another form of rule is 
what is known to pattern-makers as the 
shrinR ;rulC. By the use of this in 
pattern -making, due allowance is made 
in the pattern for the shrinkage that will 
take place in the metal of the casting. 
The common form of this rule is a 
strip of boxwood, one and one -fourth 
inches wide, and twenty -four and one- 
fourth inches long. It is divided equally 
into twenty -four parts, and each one of 
these parts is subdivided as in the 
ordinary two -foot rule. Another meas- 
uring instrument that is very useful to 
all wood workers, especially to those 
having much laying out to do, is the 
framing square. This is made of steel, 
and consists of two fiat, thin pieces of 
that metal, united at right angles to each 
other. One piece is two inches wide 
and twenty -four inches long; the other 
one and one -half inches wide and seven- 
teen inches long. (See Fig. 5). These are graduated 
along the edges of the fiat sides the same as the two- 
foot rules ; but besides these graduations there are others 



Fig. 4. 



APPENDIX 



171 



!■■■■■■■■■■■■■■■■■■■■■■■■ 



running through the center of the sides. 
One side of this blade, as the wider side 
or leg is called, is the Essex board 
measure, which is very useful for reading 
off the area in square feet of a board or 
any surface, when its length in feet and 
its width in inches are known. On one 
side of the short leg, or tongue, as it is 
called, is the bracc measurc tabic. This 
table is composed of sets of three figures, 
two of which are the lengths of two sides 
of a right angled triangle, the other the 
length of the hypotenuse. 

A try square is 

shown by Fig. 

6. The beam 

A is of wood, 

faced with a 

strip of brass to protect it 

from wear. The blade B, 

at right angles to the 

beam, is of steel. In some 

try squares the blade is 

graduated. Some try 
Fig. 5. squares are made entirely 
of metal. Fig. 7 represents a com- 
bination square; the blade A is 
moveable so it can be used at any 
length on either side of the head. The 




Fig. 6. 



172 



WOOD PATTERN MAKING 



bevel, Fig. 8, sometimes improperly called a bevel square, 
is made up of parts which are similar to those of the try 



1 1 1 1 1 1 1 1 1 1 M I i 1 1 1 1 1 1 1 H 1 1 1 1 1 1 1 1 1 1 1 1 1 1 M 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 T I ij I M 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 i 1 1 1 




Fig. 7. 
square, and have the same names. The blade is adjust- 
able to any angle with the beam, and when set the 






Fig. 8. 
thumb screw fastens it. The size of both square and 
bevel is expressed by the length of the blade in inches. 
The miter square is similar to the try square, but has the 
blade set permanently at an angle of 45° to the stock or 
beam. 



APPENDIX 



173 



The dividers are used in spacing and in laying out 
circles. They are also very useful for laying out and 
transferring angles. One way of using them for this 
purpose is illustrated at Fig. 9, which shows how to set 




Fig. 9 



a bevel at an angle of 60° and 120°. To do this, take a 
board that is planed fiat and one edge jointed, that is 
planed straight. Gauge a line at any distance from this 
straight edge; from any point on this line, with any 
radius, use the dividers to make the arc (B C). With 
same radius from (B) make the arc (D). Now draw a 
line intersecting these two points. This line will make 
an angle of 60° with the edge of the board if measured 
on one side, and 120° if measured on the other. To set 
the bevel, place the stock or beam against the edge of 
the board and swing the blade until it exactly coincides 
with the line. 

Fig. 10 shows the usual form of marking gaugc. The 
steel spur should be filed to a thin cutting edge; the 



174 



WOOD PATTERN MAKING 



long way is to stand at or near a right angle to the beam 
in such a way that when pushed along with the left 
hand, its tendency will be to pull the gauge onto the 
piece gauged. The square -shaped piece through which 




Fig. 10. 



the beam slides is called the head. The graduations on 
the beam are not to be depended on for accurate meas- 
urements. The mortise ^au^C has two spurs; one of them 
is moveable on the beam and is fastened to a brass slide 




Fig. 11. 



that is moved back and forth by a thumb screw at the 
end of the beam. This is shown at P'ig. 11. 



APPENDIX 



175 



Fig. 12 



CHISELS AND CHISEL -LIKE TOOLS 
There are two general forms 
of chisels used by wood-work- 
ers, viz., the tanged or shank, 
and the socket. These terms 
refer to the style of handle 
and to the way it is fastened 
to the chisel. Almost all chis- 
els are now made entirely of 
steel. The tanged form is 
shown by Fig. 12 , and is called 
a firmer chisel. It has a long 
tongue or tang which is driven 
into the handle, the bolster (a) 
coming up against the end of 
the handle, and so preventing 
its being driven further into 
it. The end of the handle is 
provided with a ferrule to pre- 
vent splitting. It is this form 
of chisel that is usually used 
by workers in soft woods, such 
as joiners and pattern-makers. 
The better quality of this 
form of chisel has beveled 
edges as shown. The other 
form, known as the SOCket 
firmer, is shown at Fig. 14. 
It is so called because the 
handle sets into a socket pro- 
vided for it. This form of 
chisel is more generally used 
than any other, as all classes 



Fig. 14 



176 



WOOD PATTERN MAKING 



\\ia\\ 



Fig. 15 



of wood -workers except join- 
ers and pattern-makers em- 
ploy it almost exclusively 
while even some of these 
prefer this kind because it is 
stronger than the tanged firm- 
er. Socket firmers are made 
of different weights and lengths 
for different kinds of work. 
The better grades of these also 
are made with beveled edges. 
Gouges have blades that are 
curved in section throughout 
their length, and are named 
and used like chisels. There 
are two general forms of this 
tool, viz: the inside gouge, 
(Fig. 15) and the outside gouge 
( Fig. 16) . The bevel of the 
first is ground on the inside 
of the curve ; that of the other 
on the outside; the latter is 
generally the more useful. 
They can be bought with the 
cross section of three different 
curvatures, known as quick, 

middle, and flat sweep; this is 

shown at Fig. 17, which rep- 
resents the cutting edge of 
each. The sizes of all gouges 
and chisels are designated by 
the width of the blade ; a two- 



FiG. 16 



APPKNDIX 



177 



inch chisel or gouge, for instance, has a blade that is 
approximately two inches wide. They are made in sizes 




J 



Fig. 17. 
as follows: From one -eighth inch up to one inch by 
eighth inches, from one inch to two inches by quarter 
inches. 



Fig. 18 

The Drawing Knife, or, as it is 

sometimes called, the Draw SliaVC, 

is in reality a very wide chisel, but is not used in the 
same way. It is shown in Fig. 18. 

SAWS 

The saw is one of the most useful and effective 
wood -working tools, but is perhaps the most difficult to 
keep in good order. Saws are of two general kinds ; the 
rip saw is intended to cut with the grain of the wood ; 
the cross-cut saw is used for cutting across the grain. A 
rip saw should be from 24 inches to 26 inches long and 
should have from four and a half to six teeth to the 
inch. A cross-cut saw for bcncil U C, is called a panel 



178 



WOOD PATTERN MAKING 




Fig. 19 Fig. 20 Fig. 21 Fig. 22 

saw; it should be about 20 inches long, and should have 
from eight to ten teeth to the inch. A full sized cross 



APPENDIX 179 

cut saw, called a hand SaW, is 26 inches long and should 
have from seven to nine teeth to the inch, (Fig. 19). 
The back saw (Fig. 20), is a cross-cut saw with a very- 
thin blade and fine teeth ; the blade is reinforced with a 
strip of brass or steel along its back edge, hence its 
name. The Rcy-holc saW (Fig. 21), is a narrow bladed 
one used for entering small holes for the purpose of cut- 
ting a short distance so that a larger saw may be used, 
or for cutting along curved lines. Another saw that is 
sometimes used for similar work but is somewhat larger, 
is called a COmpaSS SaW (Fig. 2 2 ) . The key - hole and the com - 
pass saw are likely to be used both across the grain and 
with the grain, and are therefore filed differently from 
those designed especially for just one of these purposes. 

As the rip saw has to cut or sever the ends of 
fibers of the wood, its teeth should have chisel -like 
points. The cross-cut saw has to also sever the fibers of 
wood, but in a different way. As the cutting is done 
across the fiber of the wood, it requires what may be 
called a SCOfing of the fiber. The friction of the other 
parts of the teeth on the wood loosen the particles cut or 
separated, and carries them away in the form of sawdust. 
The size of the teeth are governed largely by the size of 
the pieces of wood to be sawn : for cutting trees into saw 
logs the teeth are very large ; the back saw has very 
small teeth, as it is used for cutting comparatively small 
pieces of lumber. 

In the actual filing of saws the size of the tooth is 
determined by the number of teeth in a given distance. 
The size of its teeth, other things being equal, does not 
help or hinder the smooth cutting of a saw. For a rip saw 
the best form of tooth is a chisel -pointed one; the best 
form of teeth for cross -cutting effect is a triangular one. 



180 WOOD PATTERN MAKING 

These two forms of teeth are shown in Figs. 23 and 24. 




Fig. 23. 

The different angles most suitable for general work are 
also indicated in the same figures, Fig. 23 representing 
the teeth for a rip saw and Fig. 24 the teeth for 
a cross cutting saw. These should be varied accord" 
ing to the kind of wood ; they should be less acute for 
hard wood and more acute for soft wood. The kevhole 




^6CAB 



Fig. 24. 

and compass saws are filled with a combination of these 
angles. 

In fitting or sharpening a saw for use, there are four 
distinct operations to be performed: 1. It must be top- 
jointed; that is, a file should be passed along the tops of 



APPENDIX 181 

the teeth, so that they may all be of the same height and 
extend in the same general line, the line being a slight 
curve. 2. It must be SCt; that is, the point of each tooth 
is bent sidewise, adjacent teeth being bent in opposite 
directions. 3. It must be filed; that is, the individual 
teeth must be filed to a point. 4. It should be Side-jOinted; 
that is, a file or, preferably, an oil stone, should be 
passed along the side of the teeth, which will even up 
the set. 

BORING TOOI.S 

At Fig. 25 is shown the auger bit. This is the 
Russell Jennings pattern, one of the best of its kind. 
Fig. 26 represents what is called a square -hole auger. 
The boring is done by a common auger bit on the inside 
of a thin shell, which is square; the corners are sharp- 
ened, and, as the extra long spur or screw on the end of 
the auger draws it into the wood, these square corners 
cut the hole made by the auger into square form. 
Fig. 27 is the Syracuse drill bit. This is the best all- 
round drill for wood on the market. Because of its shape 
it will bore in any direction of the grain, and it will also 
operate close to the end of a piece without splitting it. 
If it becomes dull it can be easily sharpened. At Fig. 
29 is shown the Expansive bit, one of the most useful 
boring tools, because of its range in size. It can be set 
to bore any sized hole within its range. Two sizes can 
be had, one boring holes from one -half inch to one and 
one -half inches, and the other seven -eighths inch to 
three inches. Fig. 28 shows another boring tool that is 
very handy, especially to pattern-makers and to others 
who want to bore holes with smooth bottoms. It is called 
the Forstncr bit. it has no spur or leading screw, so 
must be pushed to its work. Fig. 30 is what is known 



182 



WOOD PATTEJRN MAKING 



Fig. 25. 
as the centre bit. 



Fig. 26. Fig. 26 (a). 

It is very convenient for boring holes 



APPENDIX 



183 




Fig. 27. Fig. 28. Fig. 29. Fig. 30. 

in work as it revolves in the lathe. The central spur is 



184 WOOD PATTEJRN MAKING 

not a screw, but simply a triangular point, so that this 
bit, like the last one, must be forced to its work; thus it 
can be made to do its work rapidly or slowly as the job 
may demand. 

In providing holes for screws it is found to be almost 
necessary, especially in hard wood, to countersink the 
top for the screw head. At Fig. 31 is represented one 




Fig. 31. 

form of tool used for this purpose ; it is called a COUntcr- 
Sink. At Fig. 32 is shown one of the best forms of what 
is called a bit braCC or bit StOCk. This is Fray's rachet bit 
brace. For general use the auger bit is preferred, as 
when sharp it will cut a very clean, smooth hole, and do 
it rapidly. In boring a hole through a piece of wood with 
this bit, when it is desired to leave both sides smooth, 
care should be taken not to let the bit go clear through 
from one side, but to bore just far enough so that half the 
length of the screw comes through; then remove the bit 
and iSnish the hole from the other side. Another way 
this may be done is to clamp a piece of waste wood to one 
side of the piece through which the hole is to be bored. 

MISCELLANKOUS TOOLS 

Hand screw -drivers are of several shapes. Fig. 
32(a) shows one very common form which is a very good 
one for the bench worker. Some of the other forms are 
better for special uses. The part of a screw -driver that 
enters the slot of the screw head should never be wedge- 
shaped; otherwise, when force is applied, the tendency is 



APPENDIX 



185 



to lift it from its place instead of turning the screw. The 
correct shape is shown at one side of Fig. 32(a). Brace 





Fig. 32. 



Fig. 32 (a) 



screw -drivers instead of having a handle, are provided 
with a shank for use in a brace. 

A hammer and a mallet are needed for bench work. 
The square form of mallet is for some reasons the best. 



186 WOOD PATTERN MAKING 

What is known as the claW hammer is the best for general 
bench use. The nail -set, though small, is a very neces- 
sary tool for bench work. 

The miter box, one form of which is shown 




Fig. 33. 

at Fig. 33, is an almost indispensable tool for 
bench workers. It is the most useful when small 
pieces of irregular outline, such as mouldings, have to be 
cut to a miter line, in the case of a picture frame, for 
instance. The word mitcr, when used without a qualify- 
ing word, is understood to mean the intersecting line 
between any two pieces at right angles to each other, as 
the diagonal of a square. When pieces are to be mitered 
at any other angle than 45°, the angle of the intersecting 
line is indicated in degrees; for instance, a sixty -degree 
miter. 

When pieces of wood have to be held together tem- 
porarily, for gluing or any other purpose, some form of 
clamp is necessary. The form shown by Fig. 34, known 
as hand screws, are the most used by pattern-makers. In 



APPENDIX 



187 



using hand screws care should be taken not to force the 
jaws too far from their normal parallel position; other- 
wise, the threads of the screws may be stripped, or even 




Fig. 34. 



the screw broken. There are several forms of iron 
clamps on the market, one of the best of which is illus- 
trated by Fig. 35. These are sometimes very useful, but, 




Fig. 35. 

all things considered, hand screws are the best for bench 
work. 

A grindstone of some form is a necessity for grind- 
ing the cutting edges of wood -working tools. It is to be 



188 WOOD PATTERN MAKING 

selected with reference to its grit ; one that is rather fine 
and soft is best. A power grindstone should have a 
speed of from 500 to 600 peripheral feet per minute, 
depending upon its diameter, and upon the steadiness 
and accuracy with which it runs. When a stone throws 
water from its face it is running too fast for doing good 
work in tool grinding. 

PI^ANKS AND PI.ANE:-I,IKE TOOLS 

A bench- worker's "set" of planes consists of four, 
the jointer, the short jointer or fore -plane, the jack- 
plane and the smoothing-plane. To separate these into 
a class they are usually spoken of as surfacing planes. 
These differ in length from 8 inches in the smooth- 
ing plane to 30 inches in the jointer. 

The jack-plane is the first one used in planing a 
rough surface, or in removing surplus material. If the 
surface is simply to be smoothed, then the smoothing- 
plane may immediately follow the jack-plane; but if a 
true surface is wanted the jack-plane should be first fol- 
lowed by the short jointer, and then by the jointer. With 
the last named plane in good condition, practically a true 
plane may be made. The carpenter or joiner would call 
this a surface that is OUt Of Wind. 

To test a surface during the process of planing, 
"winding sticks" or strips are used. A winding stick is 
a strip of wood of wedge -like cross -section about two 
inches wide, and with both edges straight and parallel 
to each other. Two of them are needed to testa surface, 
one being placed near each end of it. After setting them 
on the surface exactly parallel to each other the operator 
should sight across from one to the other. As the eye 
is lowered, if the one farther away is lost sight of all at 



APPKNDIX 189 

once, the surface, if straight between the points on which 
the strips set, is a true plane, and is said to be OUt of wind. 
If the farther one does not disappear all at once but the 
top edges appear to cross each other, then the surface is 
not a true plane, and is spoken of as a winding surface 
or in wind, if the surface is in wind, notice which ends 
of the winding sticks are the higher. Then if a true 
surface is wanted, plane off some of the surface at the 
points under the higher ends, and test again. In order 
to obtain the greatest advantage to be gained from the 
use of winding sticks, they should be considerably longer 
than the width of the surface to be tested. Thus the 
width of the surface is exaggerated, which is one object 
sought in using these strips. The blades of two framing 
squares answer admirably for this purpose. The use of 
these surfacing planes should be thoroughly acquired, so 
that the surfaces of any piece or pieces to be used for the 
construction of any object may be readily and correctly 
planed. As plane surfaces are to a degree the founda- 
tion for the future work to be done on them, it is very 
essential that they should be correct; if otherwise, poorly 
fitting joints will result. Good work cannot be done if 
the working faces are incorrectly planed. 

The cutting irons of all these planes are true cutting 
wedges of different widths, the width varying with the 
length of the plane. To each of these wedges is added a 
supplementary iron called a Cap or back iron, which is 
placed, as its name indicates, on the back of the cutting 
iron, thus making it a double Iron. The purpose of the 
back iron is to break the shaving as it is made by the 
cutting wedge. 

The exact way in which this is done can be explained 
better with a cut than with words alone. Fig. 36 shows 



190 



WOOD pAlTTKrn making 



how the wed^e acts as a single iron. At Fig. 37 is shown 
the double iron and the effect of the back iron on the 
shaving. As the shaving is cut and bent by the 




Fig. 36. 

wedge, its tendency is to follow the back of the plane 
iron as at A, Fig 36. As seen at A, Fig. 37, the back 
iron prevents this, by changing its course and breaking 
it before it has time to split down into the wood. 
The single iron does very good work so long as the 
grain is favorable, but when it comes to a place on the 




Fig. 37. 

board that is cross-grained, as at B, the shaving will 
split ahead of the cutting iron and leave the surface 
rough. 



APPENDIX 



191 



Fig. 38 shows the wood plane and and the advantage 
of a narrow mouth, which the iron plane shown by Fig. 
37Jacks. This, too, changes the direction of the shav- 
ing. It has also the advantage that it aids the plane in 
doing smooth work at a spot where the lumber is cross- 
grained, for the narrow mouth holds down the wood 




Fig. 38. 

immediately in front of the cutting iron, and so prevents 
its being torn up before it is cut. This is one of the 
advantages that the wood plane has over the iron, 
another being the comparative ease of working. Still, 
when everything is considered, iron planes are the best. 
Their principal advantage is that they will not warp or 
appreciably wear; consequently the face or SOlc of the 
plane is always a true plane. 

The cutting edge of plane irons should not be 
straight but slightly curved. For the jack-plane this 
curve ought to be much quicker than for the other planes. 
The jack-plane is frequently used for removing very 
thick shavings and if the iron were straight, it would 
tear out a rectangular groove for the whole width of the 
iron. This would be very likely to clog the plane and 
would also consume much more force than if the edge 



192 



WOOD PATTERN MAKING 



was curved. In a given time with a given amount of 
force applied, much more wood can be removed if the 
iron is curved than if it were straight. 

Theoretically, the outline of the cutting edge for the 
jointer and smoothing -plane irons should be straight in 




Fig. 39 

order to produce a straight flat surface, but in practice 
this is not the case. So for these irons the corners 
should be slightly rounded, or, what is better, be slightly 
curved, but the radius of the curve should be much 
larger than for the jack-plane iron. 

Fig. 39 shows the iron jack-plane, the other 
three of the set are the same shape. Fig. 40 shows one 
form of the block-plane. The principal use of this plane 




Fig. 40 

is to smooth end grain. The angle at which the iron is set 
in this plane is much smaller than that of other planes. 
This being the case, the iron, which is always a single 



APPENDIX 



193 



one, is inverted. If if were not, the angle of the cutting 
wedge would have to be so small that it would not stand 
up to the work. To prevent this plane from breaking 
over the corners of the wood, when being used on the 
end of a board or other piece, another piece should be 
placed back of the one being planed. If the board is of 




Fig. 41 



considerable width the plane may be worked both ways 
and not carried clear across. 

Another plane that is very useful to wood -workers 
is shown at Fig. 41, called a rcbatC plane. The iron is 




Fig. 42 

set asRcw in the plane and extends the wholelwldthlof th e 
face. It is used for cutting a rectangular space'called a 
rebate, into the corner of a piece of wood. This word 
has been corrupted into "rabbit." 



194 



WOOD PATTERN MAKING 



Another plane -like tool is illustrated by Fi^. 42. 
This is the carpenter's plow. Its principal use is the 
cutting of rectangular grooves into wood parallel with 
the grain. It is adjustable and can be set to cut the 
groove at any distance from the face of a board. Irons 
of different widths are supplied so that grooves of any 
width and depth may be cut. 

A plane called a dadO plane, shown at Fig. 43, is 




used for cutting rectangular grooves croSSWayS of the 
grain. Its iron is set askew. It has a depth gauge to 
regulate the depth of the groove. 

Combination planes made of metal , which may be used 
in the place of the plow, dado, matching planes, beading 
planes, etc., are on the market and some of them ?re very 




Fig. 44 

serviceable tools. Spoke -shaves have the action of planes 
but are not usually classed with them. A simple form 
is shown at Fig. 44. It has a very small face which 
adapts it for use on irregular surfaces. Another form 
which is very serviceable for quite small curves is shown 
at Fig. 45. There are several other forms of planes in 



APPENDIX 



195 



use, but most of them are designed for specific uses, 
and are not commonly used by the pattern- 
maker. 

There is one plane, however, that is used 
by pattern-makers, and which is mentioned 
in the body of this work, but represented there 
in the wooden form, that should be noticed 
here ; that is the latest form of iron core box 
plane, and is represented by Fig. 54. 



to 

6 




Fig. 54 



CUTTING WEDGES 

From the wood -worker's point of view, the chisel is 
the typical Cutting tool. It has two operations to perform 
when in action, viz.: Cutting the fiber of the wood, and 

breaking, crushing to one side, or bending the wood out of 

the way, so that the cutting edge may go on with its 
work. Every cutting tool is a wedge, more or less 
acute. To widen the cut the wood must be bent; this 



196 WOOD PATTERN MAKING 

the cutting wedge of the plane does, and thus forms a 
shaving. The chisel, when driven into the wood, as in 
cutting a mortice, crushes the wood and so widens the 
cut. When the wedge is driven in parallel with the 
grain, the fibers are pressed apart,thecut is widened and 
the wood split. It can be demonstrated that much less 
force is required to carry the wedge forward when first 
entering the cut than after it has extended into the 
material for some distance. It is reasonable, therefore, 
to suppose that the larger part of the force applied to 
form a shaving or chip, is consumed in this bending or 
crushing, and a very small part by the actual cutting of 
the fiber of the wood. A very acute angled wedge will 
do a given amount of work with less force than one not 
so acute. But the one with the larger angle will do the 
actual cutting as easily as the other. The angle of the 
wedge has very little to do with the force required to do 
the cutting, at least up to any angle that would or could 
be used for cutting wood. The acuteness is limited only 
by the strength of the steel, so it must vary as the kind of 
work and material varies. A more acute one may be used 
for soft wood than for hard wood. And again, a larger 
angled wedge is needed in a chisel that is to be used or 
driven to its work with the mallet than in one that is to 
be used with the hands only. 

If it was insisted on that a cutting wedge should 
always have its maximum of delicacy, it would necessi- 
tate that the angle be changed for almost every shaving 
or chip made. This would be impracticable, so that the 
results of the experience of wood -workers may be 
expressed as follows: "Make the cutting wedge as 
acute as the metal will allow without breaking, when 
fairly used." The angle of the wedge for all wood- 



APPENDIX 197 

cutting tools for general use should be from 25° to 30°. 

The sharpening of a cutting wedge requires con- 
siderable care and skill, if it is required to do first-class 
work with it. If the chisel or other edge tool is new, or 
very dull, it must first be ground. This is best done on 
a medium grit, soft grindstone. Emery wheels are largely 
taking the place of grindstones for this purpose. Greater 
care is necessary in the use of emery wheels than with 
grindstones for grinding WOOd-WOrkJn^ tools, for the 
wedge being thin, the temper of the steel is very liable 
to be drawn by the heat generated by the friction. In 
grinding a cutting wedge, the grindstone should revolve 
toward the cutting edge. The correct position in this 
regard, and also to produce the best angle for general 
use is shown in Fig. 46. Plenty of water must be kept 




Fig. 46. 
on the stone during the process of grinding. The water 
serves two purposes; one is to reduce the temperature 
generated by friction, the other to keep the stone clean 
or to carry off the particles of sand and metal loosened in 
the process of grinding. The surface produced by the 
grinding is called the bcvcl. 

As the coarse grit of the grindstone will not produce 
a clean, smooth cutting edge; the tool will have to be 
whetted. This is done on an oil stone, either natural or 
artificial. The latter kind, if made by a reliable firm, is 
the best, as it wears more evenly. The tool, while held 



198 WOOD PATTERN MAKING 

in such a position that the heel of the wedge does not 
quite touch the stone, should be carried back and forth 
along the whole length of it, care being taken not to give 
the tool a rocking motion, which would produce a curved 
instead of a straight line. This operation should be con- 
tinued until a slight wire edge is produced on the back, 
as the straight side is called. The wire edge must be 
removed in order to produce a sharp edge that will cut 
smoothly. To do this, lay the tool on its bacR, flat on the 
oil stone, and give it a few light strokes toward the edge. 
Great care should be taken not to raise the handle of the 
tool, as that would bevel this side of the wedge and 
impair the proper working of the tool. There are two 
tests that may be used to determine if the edge is sharp. 
One by the eye, the other by the sense of touch. If a 
sharp edge is examined by the eye, it will be noticed that 
a dull line appears where the edge is. If the edge is not 
sharp, a bright line will be seen. The more dull the 
tool is, the larger the bright line will appear. To test by 
the sense of touch, place the thumb or finger on the edge, 
and try to move it along the edge. If it is not sharp, no 
difficulty will be found in doing this. If, however, the 
edge is sharp, a clinging or pulling sensation will be felt. 
The best test, however, is to cut wood in the same direc- 
tion as the work to be done. If the surface cut is smooth 
and glossy, the tool is sharp. If the tool is dull it will 
cut a surface that is rough and dull to both touch and 
sight. 

LAYING OUT WORK 

The production and location of lines is one of the 
most important parts of wood work, as of all mechanical 
work, in the production of work of a definite size and 
shape. Any carelessness in this direction will always 



APPENDIX 199 

make itself manifest in the finished product. This is so 
much the case that one who is habitually careless in this 
regard seldom makes a good mechanic. Let it be under- 
stood at the outset that a scratch is not a line, and that 
patience and accuracy in the making and locating of lines 
is one of the first requisites to success in all mechanical 
manipulations, and in the production of all articles made 
by mechanical processes. 

The tools used for marking lines are four, — the 
chalk line, pencil, gauge and knife. For bench work the 
knife and gauge are the most used. The knife is used 
for marking across the grain, and should have a sharp 
point so that it will cut into the wood, not merely scratch 
it. In making a mark where a cut is to be made with a 
saw, the lines may to advantage be cut 1/32 of an inch 
deep. The gauge is the best implement for 
marking lines lengthwise of the grain. A great deal 
more might be said about this part of wood -working, 
—laying out work, as it is usually called— but space 
forbids. 

PATTERN TURNING 

The term WOOd turning is generally understood to 
mean the making or forming of any circular form 
required of wood, while revolving at a high rate of speed 
in some form of lathe. Wood turning is done in two dis- 
tinct ways; first, along or parallel with the grain; and 
second, across the grain, or, as it is sometimes called, 
plankwise. Wood turning may be divided into two kinds, 
cabinet turning, by which balusters and other decorative 
articles are produced ; and pattern turning, a method used 
by pattern-makers, by which the many circular forms 
required in that trade are made. The same tools are used 
on both kinds of turning, but the processes are, in some 



200 



WOOD PATTERN MAKING 



respects, quite different. The cabinet turner is more 
concerned as to the beauty of outline and finish than 
with exact size, and uses methods that will accomplish 
these results. The pattern turner, on the other hand, 
must have exactness in size, the finish being a secondary- 
matter. This being the case, whereas the cabinet turner 
actually cuts the fibers of the wood, the pattern turner 
uses what is called a SCrapin^ cut for most of his work. 
A common form of turner's lathe is shown by Fig. 47. 




Fig. 47. 



In the figure, A is the bed, B is the head StOCk, C is the 
tail Stock, D is the Stcp cone pulley on which the belt runs 
that drives it and the Splndle G, and with it the driving OF 



APPENDIX 



201 



fork center, which in turn drives the work. The fork 
center is drivenlinto a tapered hole in the spindle, and is 
held by friction only. In the tail stock is the bacR Center, 
H. At F is the tool or hand rest. 

Fig. 48 shows an enlarged view of the most common 




Fig. 48. 

form of fork chuck. The fork chuck at the left hand, 
and the back center at the right, make up the common 
appliance for holding work in the lathe, when the turn- 
ing is to be done lengthwise or parallel with the grain. For 
turning plankwise or across the grain, there are several 
kinds of Chucks employed, the simplest being the SCreW 
chuck, shown at Fig. 49, in two forms. A face plate is 
shown in the center of Figs. 62 and 63, pages 122 and 
123, and a chuck for large work at Fig. 62, and one at 
Fig. 63 adapted to still larger work. The pieces shown 
at A, Fig. 62, are not necessary, but they area great con- 
venience when it is required to hold work on the chuck 
with hand screws, as in gluing up work. If the chuck 
has such a rim, the hand screws may all be set open the 
same distance, and therefore quickly applied, which is 
necessary when using glue. For small work, a chuck 



202 



WOOD PATTERN MAKING 



may be simply a disk of wood. Each chuck must have a 
face plate fastened to it during its use. There are several 
different ways of fastening work to these chucks, gener- 
ally determined by its size and shape. It may be fastened 
with screws or nails, it may be glued directly to the 



<miu 




Fig. 49. 
chuck, and it may be glued to paper already glued to the 
chuck. When this last way is used, the work may be 
taken off without damaging it, because the paper will 
split. When it is glued directly to the chuck it will 
have to be cut off, so this way is not usually employed 
except for patterns of thin CPOSS Section, such as pulley 
rims, that can be easily cut through. Besides these plain 
chucks, several other forms are in use for special work, 
one of which is represented by Fig. 50, and is called a 
cup chuck. One of its uses is to hold a sphere in the lathe 
while it is being given the finishing touches. Some of 
the specific uses of these appliances are described in the 
body of this volume. 



APPENDIX 



203 



Not many different forms of tools are required for 
pattern turning, but quite a number of different sizes of 
the same form are needed. The first to be noticed is the 
turner's gouge, shown by Fig. 51, and the Skcw, or tum- 




FiG. 50. 

Ing chisel, illustrated at Fig. 52. These two, in their dif- 
ferent sizes are the only tools used by the turner for cutting 
the fiber of the wood. All theothers are really scraping tools, 
and do not actually cut. The other tools most used for 
pattern turning are illustrated by Fig. 53. At A is shown 
a pair of the ordinary scrapers, the tool most used on 
flat and convex surfaces. At B is shown the round -nosed 
scraper, used for concave surfaces; several sizes of this 
are needed for a medium range of work. At C the ordin- 
ary parting tool is shown. This is a very useful tool for 
working wood plankwise ; its special form gives clearance 
in whatever position it may cut the wood. The tool 
shown at D is also a very good tool for turning wood 
across the grain, especially if a large amount of wood is 
to be removed. This it will do rapidly and easily. It is 
called a diamond point parting tool. At E, in Fig. 48, is 
shown a straight scraper, which is very useful for finish- 



204 



WOOD PATTERN MAKING 





Fig. 52. 



Fig. 51. 



ing large straight surfaces. It is made from a firmer 
chisel that is worn too short for its original use. Indeed, 
worn-out chisels of this type make first-class turner's 
scrapers. All the scraping tools, except those shown at 
A and D, may be made of these and will serve their pur- 
pose admirably. The two noted above are sometimes 
needed longer than the others, and are better if made of 
heavier stock. 



APPENDIX 



205 



The art of turning can be learned by the student only 
in the same way that any other mechanical trade or craft 
is learned, i. e., by actually doing the work and perform - 




Fig. 53. 
ing the operations involved in the practice of that art. 
This being the case, only a few simple directions will be 
given here. These directions may best be given by 
explaining the operations that must be performed in turn- 
ing a cylinder. The first thing to be done is to saw 
out the stock square, with the sides about one -eighth 
inch larger than the diameter of the proposed cylinder. 
Next make a center mark on each end by drawing 
diagonal lines across it ; at these points the lathe centers 
are to enter. To set the work in the lathe, place one end 
against the driving center, or head center, and with a 
hammer or mallet drive on the other end until the chuck 
has entered the wood far enough to revolve the wood 
against the tools ; now while holding the right hand end 
in the left hand, slide up the tail stock with the right 
hand until its center touches the wood, and clamp it to 
the bed. With the handle connected with the tail center, 
push the center into the right hand end far enough 



206 



WOOD PATTERN MAKING 



to make it secure. Adjust the tool rest so it will just clear 
the corner of the piece when revolving:. It is a good 
plan, before applying the power, to giv^e the belt a pull 
with the hand to ensure that everything is clear. 

The gouge is the first tool to be used on this kind of 
turning; the cutting done by it at this stage of the 
work is termed the roughing CUt. The gouge is so held 
that a center line through the tool will be perpendicular 
to the axis of the work. The bevel of the cutting wedge 
should be held tangent to the proposed cylinder, and 
rolled on its side as indicated by Fig. 55 at A. The 




Fig. 55. 

direction in which the tool is moving is indicated by the 
arrow in each case. In this position the angle of the cut 
will be about 25° to 30° with the axis of the cylinder, 
which is the best for this kind of turning. The gouge is 
used by good turners for doing a very large proportion of 
the work on plain cylindrical and concave surfaces. 

Plain cylindrical and convex surfaces are finished 
with the turning or skew chisel, the only other cutting 
tool used by turners. Its use requires a great deal of 
skill on the part of the operator. On account of its shape 



APPENDIX 



207 



it has a great tendency to rip or tear into the work with 
its long corner. One reason for its so doing lies in the 
fact that it Cannot be laid flat on the tool rest, but must be 
supported as shown at Fig. 56, and at A and B, Fig. 57. 




Fig. 56. 

This being the case, the keeping of the edge of the 
chisel in its proper position and angle with the work 
depends entirely on the skill of the workman. This skill 
cannot be imparted, but some suggestions can be given 
that will aid the student in acquiring it. Do not let the 
chisel cut above the central point of the length of the 
cutting edge, that is at D, in Fig. 56. Retain a firm grip 
on the handle with the right hand. 

The bevel, like the gouge, should be laid on the 
cylinder exactly tangent, and held so that the handle is 
perpendicular to the axis of the cylinder. As Onc COmcr 
only of the chisel touches the rest, it is very difficult to 
keep it in its correct position. If the bevel is exactly 
tangent, it will not cut; so it must be tipped enough to 
be tangent to a circle slightly smaller than the one 
already cut. This is best done by simply rolling the 
chisel with the hand until it cuts a shaving of the desired 
thickness. As a general thing, the cylinder should be 
cut almost to size with the gouge, leaving only a shaving 
or two to be removed by the chisel. 



208 



WOOD PATTERN MAKING 



Pattern-makers do almost all this finishing with a 
scraper like E, of Fig. 48. The position of this tool for 
scraping plain cylindrical surfaces is, as shown in Fig, 
58, exactly on the diameter of the cylinder. The cutting 
of shoulders like those in Fig. 57, and also the square 





Fig. 57 



ends of the same figure is done with a skew chisel. The 
chisel is held as there shown, that is, at a slightly 
larger angle than the one at which it is sharpened ; so no 
part of the Cd^C, except the extreme point, should touch 
the wood. The ends of nearly all plain cylindrical pat- 
terns have to be made COnVCX. To make them so, the 
chisel may be held with the center line of its length per- 
pendicular with the axis of the cylinder, while at the 
same time the edge of the chisel is perpendicular. For 
making other forms in the lathe, the tools shown in Fig. 
53 are used. These are all scraping tools. 

SHARPKNING LATHE TOOLS 

The cutting wedges of the turning gouge and the 
turning chisel are sharpened in the same way as other 
cutting wedges. The wedges for soft wood, however, 
should be more acute than the bench chisel for general 
work. The wedge of turning chisels for use in soft wood 



APPENDIX 



209 



may be ground to an angle of 20°, and must be kept very- 
keen if good work is to be done. The rou^hin^ §OU^e 
should have a wedge of 30°. The scraping tools should 
have wedges of about 45°, and be ground on one side 
only, as shown. As the cutting edge of the scraping 




Fig. 58. 

wedge is on the side instead of on the end, as in the 
cutting wedge, it requires a different treatment to secure 
the best results. After sharpening the chisel in the 
usual way, place it on the oil stone on its bevel, and, 
while holding it in that position, give it two or three 
strokes parallel with the back. This will give a con- 
tinuous wire edge, which is just what is needed. Push- 
ing the chisel back and forth in the usual way also pro- 
duces a wire edge, but it is a serrated one, and therefore 
is quickly dulled. 

TOOLS FOR MEASURING TURNED WORK 

The special tools for measuring turned work are 
shown at Figs. 59and60. The former is the outside caliper, 
the latter the inside caliper. The outside caliper is used 
for measuring the outside of round or cylindrical work, 



210 



WOOD PATTERN MAKING 



the inside caliper for measuring holes and cavities either 
cylindrical or of other forms. The outside caliper may 
be used when the work is revolving, provided it is very 





Fig. 59. 



Fig. 60. 



nearly cylindrical. The inside caliper should not be 
applied to work that is revolving, as it is likely to be 
caught by the wood and jerked out of the hand. The 
common two -foot rule is used for measuring along a 
cylinder, when the caliper would be unhandy. When a 
number of pieces, balusters for instance, are to be made 
alike, a special measuring device is usually made use of 
by turners. It consists of a light stick of wood with 
sharpened wire brads driven into it at certain points along 



APPENDIX 211 

its length, where the deeper cuts are to be made. After the 
piece is turned down roughly to size, this scriber, as it is 
called, is laid on the tool rest in such a way that the 
sharpened nails will just touch the cylinder as it revolves, 
thus making a line around it where it is to be cut. This, 
of course, saves time, for the reason that the lines are all 
made at once, and the distances between them are meas- 
ured at the same time for all tbe pieces. It is not often, 
however, that the pattern-maker has any use for this 
device, as his work is seldom duplicated. 



INDEX 



A 

Amount of shrinkage in small 

patterns, 17. 
Annular patterns, 61, 140. 
Angles, 173.. 
Arms of wheels, 99. 

B 

Bevel gear patterns, 120. 
Bit,sqr. hole, 182. 

— auger, 182. 

— center, 183. 

— drill, 183. 

— brace, 185. 

— countersink, 184. 
Black varnish, 26. 
Boxing up patterns, 59. 
Brads, 27. 

Brace bit, 185. 

Brackets, 50. 

Building up thin discs, 56. 

—patterns, 59, 61, 140. 
Brass, shrinkage of, 16. 

— for patterns, 23. 



Cause of distortion in cast- 
ings, 19. 
Castings, distortion of, 19. 
Casting of gland, 67. 

— of double flange bush- 
ing, 77. 
— of hook lever, 49. 
— of pulley, 93. 
— of pipe elbow, 129. 



— of pipe bend, 126. 
— of steam chest cover, 
132. 
Cabinet turning, 199. 
— making, 1. 
— maker, 1. 

Chords of curves, 61. 
Chucks, 122, 123, 201, 203. 
Chuck, cup, 203. 

—fork, 201. 

— large, 123. 
Constructional joints, 55. 
Copal varnish, 26. 
Cores, 37. 
Core box, 39, 41. 

—prints, 38, 40, 42, 44. 

— box, finishing of, 75. 

—board, 134. 

— strickle, 134. 

—box plane, 72, 195. 

— box, conical, 74. 
Cope, 6, 7, 10. 

— bars, 7. 

— sand, 8, 9. 
Contraction, 15. 
Concentric, 161. 

— layers, 161. 

— hubs to be, 105. 
Corners in patterns, 30. 

— inside, 30. 

— outside, 30. 
Counter ribs, 57. 
Cylindrical layers, 161. 

— patterns, 61. 

-cores, 39, 110 



INDEX 



213 



D 

Distortion in castings, cause 
of, 19. 

— caused by shrinkage, 18 
Dividers, 173. 

— laying out angles with, 
173. 
Double shrinkage patterns, 23. 

— allowance for, 23. 
Dirty mold, 32. 
Drawings, reading of, 154. 
Draft on patterns, 13, 14. 
Diagonal lines, 

E 

Engineer, requirements of the, 4 
End wood, 25. 

— grain to be sized, 25. 
Emer}' wheels, 197. 

— for grinding tools, 197. 



Face plate, 201. 

— plate lathe. (Frontis- 
piece.) 
Faces, working, 189. 
Framing square, 171. 
Fillet, 30. 
Fillets, making, 33. 

— in patterns, reason 
for, 31. 

—leather, 32. 

— wood, 33. 

— wax, 34. 
Filing saws, 179. 
Fitting saws, 179. 



Gauge, marking,, 174. 



—mortise, 174. 
Gears, 108. 

—bevel, 120. 

—spur, 108. 

—the laying out of. 111, 
113, 117, 120. 

— tooth curves for, 117. 

—patterns for, 108. 

— patterns, arms for, 120. 

— patterns, teeth for, 118. 

— patterns, tooth blocks 
for, 113. 
Glue, 24. 

— joints, 24. 

— use of, 24. 
Gouge, 175. 

— outside, 176. 

— inside, 176. 

— paring, 176. 

— turning, 204. 

Grindstone, 197. 

Grinding cutting wedges, 197. 

—chisel, 197. 

—plane iron, 192. 

H 

Hand screw, 187. 
Handscrews, use of, 187. 
Handsaw, 178. 



Iron planes, 190, 192. 
— castings, 2. 
— shrinkage of, 16. 



Jointer plane, 188. 
Joints in patterns (construc- 
tional), 55, 



214 



INDEX 



— in patterns (mold- 
er's), 46. 

K 
Knife, draw, 177. 

L 

Lags, patterns built of, 60, 61. 
Lagging, 60. 
Lagging up, 60. 
Loam, 133. 

— patterns, 134. 
Leather fillets, 32. 

— the application of, 32. 
Lugs for machinist's use, 140. 

M 

Making pattern pins, 79. 

— semi - circular core 
box, 70. 

— pulley patterns, 93 
Marking gauge, 174. 
Master patterns, 23, 151. 
Metals, shrinkage of, 16. 
Measuring tools, 169. 
Mitre square, 172. 
Mahogany, 22. 
Mortise gauge, 174. 
Molding, 6. 
Mitre box, 186. 

N 

Nails, 27 

Nails, best for patterns, 27 

Nowel, 7. 

O 

Oil stones, 197. 
Open joints, 58. 



Parting, pattern-maker's, 77. 

— molder's, 9. 
Patterns, construction of, 66. 
Pattern-making and molding 
(connection between), 
2, 3,5. 
Pattern pins, 79. 

— wood for, 20. 

—lathe, 54, 200. 
Pegging segments, 99. 
Plane, core box, 72. 

—rebate, 193. 

—dado, 194. 

—plow, 193. 
Planes, surfacing, 188. 

— combination, 194, 

— wood, 191. 

—iron, 190. 
Pins, pattern, 79. 
Pulley, pattern for, 93. 



Segments, building with, 61. 

Screwdriver, 185. 

Spoke shave, 194, 195. 

Shrink rule, 17. 

Shake, allowance for, 17. 

Sprue pm, 9. 

Saws, 177. 

Saw, hand, 178. 

—back, 178. 

—keyhole, 178. 

— compass, 178. 

—band, 82. 

— circular, 65. 
Scale on castings, 18. 
Scales for measuring, 170. 
Scrapers, 201, 205. 



INDEX 



215 



Scraping a surface, 209. 
Sap side of board, 21, 166. 
Sandpaper, 23. 
Sandpapering machine, 29. 
Shellac varnish, 26. 
Shoot board, 96. 
Shooting joints, 96. 
Shrinkage of iron, 16. 

— of brass, 16. 

— of steel, 16. 

— of aluminum, 16. 

— double, 23. 
Screws, 27. 

— in end wood, 28. 
Stove pattern-making, 145. 
Strickles, 134. 
Square, framing, 171. 

—try, 171. 

— combination, 172. 
Stone, oil, 197. 
Surfacing planes, 188. 
T 

Taper on patterns, 14. 
Tools for woodwork, 167. 
T bevel, 172. 
Trimmer, 95, 98. 
Turning lathe, 200. 

—tools, 204, 206. 



— cabinet, 1. 

— patterns, 199. 

— in cup chuck, 203. 

—parted pattern, 80. 
Thin discs, bnilding of, 56. 
Thin boards, building of, 56. 
Template, 111. 

V 

Varnish, yellow, 26. 

— red, 26. 

—black, 26. 
Vertical sides of patterns, 15. 
Vise, pattern-maker's, 163. 

W 

Warp, allowance for, 18. 
Warping in wood, 165. 
— in castings, 19. 
Wheels, gear, 108. 

Wood, drills, 183. 

—turner's lathe, 200. 

— for patterns, 20. 

— fillets, forming of, 33. 

Wheels, gear, 108. 
— arms of, 99. 
-teeth of. 111. 
— laying out, 117, 121. 



WAYS 1906 



